Do you ride it every day and commute on it or is it you sunny sunday rider which attracts attention from bike enthusiasts where ever it goes? Old production japanese bike you ride daily? Powder coat it. 1970s columbus built italian racer fitted with campagnolo? Wet paint and decal repo... I guess there must be a grey.. say a late 70s nishiki superbe or something.... I would say if you ride it frequently then powder coat. Powder coats can look better than paint if done by an expert.