Hi there, got a masi gran criterium out of the dumpster and would like any help on dating this cool bike. It seems to be all original except for the rear wheel and tire. The only #'s that I can find are M615 or possibly M61.5 on the bottom bracket. The #'s are stamped but the decimal pt. is not, but is definetely orig looking? Thanks for any help you can give. I tried to include pics but file size was too large.