way ahead of the game
Hey,
You're way ahead of the game. You've (the dacal has) done most of the work already. You should coat the decal on the seat tube with clear fingernail polish to protect it. Ishiwata, who previously made frames for Fuji, went out of business in 1992. So, the year and the maker Tange fits. Additionally, you might try pulling the fork and taking a look at the steer tube. It will probably say Tange, too. I'll add an example. Try the Fujibikes.com website and click on 'United States', 'Contact','general email:'. The guys in that department are very responsive. Give them the BB S/N, who knows?