nice nishiki. since u used degreaser, be sure to apply lube on the appropriate spots (ie chain, gears).

if its just surface rust, you can:

1. just leave it be to give it character
2. you could sand the spots very well, apply rust inhibitor, paint, clear coat. but if your doing it for looks, beware a spot paint job may look worse than what u had to begin with.
3. if u wanna go balls out, a complete paint stripping, metal treatment, and powdercoating would be it. probably overkill.

i vote #1. ride the bike for a few months first.