Sources:

1) We received the following information from Michael Johnstone, who played bass in 'The Misfits' from the fall of 1963 until the end of 1964:

The drummer in this version of the Castle Heights band was Howard Smith and the alto sax player was Dave Johnson.
There was not too much singing in that band, including Gregg, who only played guitar then. No keys or vocals until a couple years later.
We played a gig at an off campus teen dance in Lebanon the night JFK was shot. [November 22, 1963] That lineup didn't last too long because just before Xmas 63, Duane got kicked out for pushing a kid down the stairs. I never knew of that incident till hearing of it from another guitar player named Rick Clifton from those years at CHMA few years ago who called me right after the Poe book [Randy Poe: 'Skydog - The Duane Allman Story'] came out. All I knew before that was that he left school one day. Gregg hung on for a few more months and then he left too. The band went on with Clifton, me, sometimes another guy on guitar named Robert Thames, Johnson and Smith. Kind of a rotating lineup post Allmans. I myself got outa there around a year later. I went home for Xmas 64 and never came back. I wanted to start playing pro. I did finish high school in Newport News, Va and then hit the road for about 50 years ending up in L.A. playing blues-rock, R&B, jazz and Bakersfield style country music on guitar, mandolin and pedal steel.
I ran into Duane and Gregg a handful of times on the road or when they passed thru Tidewater VA in the late 60s-early 70s. I last spoke to Duane backstage at the Civic Center in VA Beach a few weeks before his death.


2) On October 4, 1998 Michael Johnstone posted the following information on:
http://www.castleheights.com/chma/UserDataFile.html

I first came to Heights in my junior year of high school in the Fall of 1963. I was send there because my dad, a lifer in the army, thought I was spending to much time playing my electric guitar and not enough time with my schoolwork. He let me take my guitar with me to heights, though, I guess figuring it would be OK to have and play it under a more controlled environment.
I'll always remember the very first day at school. My dad had driven me from Virginia and we got there a couple of days early. There I was alone in my room and I heard someone playing the best guitar I had ever heard, so I followed the sound down the hall and down the steps (my room was on the top floor of "Main") and when I came to the room and knocked on the door, a red haired guy answered and said "Hi! I'm Duane Allman." I introduced myself and told him I played too, and he said "Great Because my brother Gregg and I always try to have a little band here at school." Needless to say, I jumped right back into music and in the process, I learned more from Duane and Gregg Allman about music than I ever had in Virginia.
It didn't last too long though, cause Duane got kicked out of school not too far into the school year. Gregg lasted somewhat longer but he, too, didn't last out the school year.
There were others there at Heights who played music and I played with them all - Robert Thames, Rick Clifton, Dave Johnson, Howard White, and Jay Wolf to name a few.
Meanwhile, I got into my studies and joined the drill team. A lot of historic shit happened during my stay at Heights - Kennedy was assassinated, The Beatles came on the scene and 'Nam was starting to happen. I came back for my senior year in '64 but too many demerits conspired to take the fun out of it (something about an unauthorized weekend trip to Nashville involving alcohol). Anyway, I longed to get back to civilian life so I could embark on my music career and I made this feeling known to Col. Ingram and he agreed that maybe I should leave. So, somewhat reluctantly, and somewhat gladly I took my leave of CHMA in Early 1965.
I went back to Virginia and graduated from public school but I have always wished I'd stuck it out at Heights till graduation.
I did have a career in music and after 10 years on the road playing guitar, I moved to California and started to work building and operating recording studios for legendary rock piano man Leon Russell. This lasted 5 years and let to other jobs in other studios and in 1985 I built my own recording studio called "Class Act." I have kept playing music and in '75 I added pedal steel guitar to my act, and it served me well. In '77, I played for a while with country artist Charlie Pride. In August of this year ('98), I relocated my studio from North Hollywood, CA 10 miles north to the horse country of Sylmar, CA. The studio is much nicer, much larger, and features 32 tracks of digital recording.


3) Randy Poe: 'Skydog - The Duane Allman Story', page 10 (Backbeat Books, 2006):

For at least a few months in the latter part of 1963, Duane and Gregg were both going to CHMA at the same time. Mike Johnstone, a fellow guitarist, was also at Castle Heights that year. “I had started playing in bars, underage, and playing whenever I could at school dances and stuff, and doing all the activities that go along with that—like drinking and just being a fuck-up in general,” Johnstone says. “My dad was concerned, so he said, ‘I’m gonna send you to Castle Heights. I think this is the best bet for you at the moment—you need to be going where there’s a little more discipline. And you can bring your guitar.’
“So I said, ‘Okay, I’ll do it.’ I didn’t really want to, but I went. The first day I was there, there were very few people in the dormitories because I was a day or two early. Now, at that time, there was a popular song on the radio called ‘Memphis’—an instrumental by Lonnie Mack. It was the best guitar playing I’d ever heard. All the guitar players were going, ‘How could anybody ever play as good as that? That’s the new bar. That’s how good you have to be now.’ And when I got to the school, I heard this song wafting down the hall.”
Johnstone thought he was hearing “Memphis” on a radio in someone’s dorm room—until he realized that the music kept starting and stopping.
“I followed the sound,” he continues, “and it was coming out of this room one floor below me. I knocked, and a guy comes to the door. It was Duane Allman—a redheaded guy with a guitar hanging around his neck. He had it plugged into an old amp, and he was playing the song just as good as Lonnie Mack. So I thought, ‘Well, shit! I gotta make friends with this guy.’ I went in and sat down, and we hit it off right away. He told me he had a brother who was at the school, and he had a guitar too.”
Duane took Gregg’s guitar out of the case and handed it to Johnstone. “Gregg didn’t play keys in those days, just guitar. I told Duane that I had a guitar and an amp—and that I had a bass. He said, ‘You have a bass? Nobody has a bass! We need a bass player.’”
Duane had already rounded up a drummer and a sax player, so with Johnstone on bass he had a band. “We rehearsed down at the auditorium there at the school and played school dances. We did what I call black rock & roll—the early R&B things: Bobby ‘Blue’ Bland and Ray Charles and James Brown. I remember we played ‘Stormy Monday.’ I was coming out of surf music—that was my deal. I got started listening to Chet Atkins, which led me to the Ventures. Duane was into that, too, but he was more into B.B. King and things like that.”
Duane was also developing his ability to lead a band. According to Johnstone, Allman would “kick the ball along, keep the thing moving. I’ve been to a lot of rehearsals and been in bands that didn’t know how to do that. The average person may not even appreciate what a bandleader does. The good ones, they don’t demand respect—they command respect. There’s a difference. He wasn’t a bully or anything; he just knew exactly what he wanted to do. He was a leader.