I remember a shirt very much like what you describe, though there was no Family Circus circle, and Jeffy was the bottom (I think). This was a shirt sold on my college campus (in NM) as a fund-raiser, and I thought it had been drawn by a student there. Could the shirt I'm talking about have been a knockoff of yours, or vice-versa? Or are we talking about the same shirt? This was back in 1991.
I had one for years sitting in my drawer, but I was too embarrassed to ever wear it in public. I ended up giving it to a friend who I thought was just gutsy enough to wear it, but I don't think he ever did either.