Aren't you guys going to have eventually move up in a couple of years anyway... unless you want SPA to represent antique aircraft only.
I've got a mid 90's Hydeout, compared to today's F3A planes it's a pensioner.
Even the 80's 1.20 powered somethings are 23 plus years old! Yet don't qualify to take part at a SPA event?
You guy's have rules that keep you firmly planted in the 60's early 70's.
So what's going to be the next step?
Maybe you should start thinking about a New Class... before somebody else does?