I have a Nishiki Custom Sport from the early 80's. It has a nice chromo frame and a nice Sugino GS crankset. It also had alloy wheels, but they were trashed. The cranks and frame were worth (to me) what I paid.
Can you post some pics...........it would really help in determining if it's worth rebuilding/upgrading.
Certified thread killer
'79/'80 Sekai 2700, Early 70's PX-10, '90/'91 Club Fuji, '83 Miyata 610, '70ish Zeus Gran Sport, '88 Centurion Ironman Master, '89 Bridgestone RB1, '99/'00 Gunnar Rockhound, '99 Surly Cross Check, '09 Surly Cross Check, Fuji Saratoga