HI Scott,
I am going to say the Juno was first built by Billy in 1975. He used it at the Lincoln NATS in 1976.
I should know the Europa and RD-1 since Aaron and Robby were really in communication over both as Aaron used an RD-1 in his first official "stunt contest" in 1992! LOL!! But the memory isn't complying right now. 1991 or 1992 on the RD-1 is my "best guess". The RD-1 was the "forerunner" of the Prowler. Scott Smith kitted the Prowler after conferring with Bob on the RD-1, so it would be the same "year", AFAIK.
Bob posted quite a bit on the Europa a month or two back.
What "other planes" do you want added?

Bill