Hi,
I found this thread since my 19 year old son who likes to fix up old bikes asked me what kind of bike I had in my youth. I thought back to the Nishiki Olympiad which my parents got me for my 12th birthday in 1972. It was white, cost $120 (they payed 100, I payed the other 20 and it was a big deal to me).
I loved that bike and rode it lots, until my later teens when I got cold feet about bike riding in traffic, I felt safer riding horses (they have an instinct that keeps them from falling over). I took my bike to a remote island where, in the end, I left it too long under a fir-tree.
About two years ago I went back to biking now that I live in Europe and there are a lot of safe-feeling bike paths and comfortable bikes (I got a Kettler Traveller).
I can't tell you anything technical about that Nishiki. It was white and did NOT have a red and black seat-tube decal. I can't remember any decals on it.
Thanks for the memory trip!