As far as I understand for new Tokais there is a kind of domestic line (in the catalogue) which follow the yen=model number rule and there some models which are custom ordered by Tokai country distributors like Tokai Germany, Tokai Switzerland, etc. The 2nd ones dont follow this yen= model number rule. Strats are often called "TST-50" but specwise they are more a highend model. Tokai Germany sold TST-50s for about 1500 Euro....
There is another TST-50 from Tokai Switzerland on Reverb with a Flamed maple neck, etc... asking price more than 2000 Euro...
I just aquired a used TST-50, which just looks awesome.... 2 piece ash body, maple neck with satin finish, leighweight....