It's possible Gerry, the fellow with all the good stuff, may have something, but I doubt it. I haven't been over to visit him, yet, but he has invited me over.
I could check my OM for the RT-1020L to see what's compatible, so a photo would be nice. It may be a standard 5, or 7 pin DIN male I'm guessing on the JT-211.
Nando.