I got my owner's manual from my local dealer. I don't know how it differs from a 26 year old one except it's not old. :-) Make sure they don't sell you one that covers R100s and the other bikes, as that one is for the later R65s that share a frame with the rest of the line. The correct book for you only covers R65s and R45s. They're a bit over 20 bucks if I remember right.
Good luck,
Ed