Wow thanks T-Mar , your knowledge and fast response are definitely appreciated !I had kind of figured out after the fact that it could not be a 1981, too modern. 750$ was a lot of money in 1991. The only problem I have with the bike is that it is going to be hard to fit even 700x32c with fenders , so I may put it back to original if I find some nice touring bike with 26'' wheels or a 700c with beter clearance.
The shifter and RD have found their way on a Kuwahara touring bike , the rest I'm keeping .