Hi Philip
With a 5 digit code its probably going to be a TST-50 from the mid 80s. Things to check for:
1. Oval numbered sticker on back of the neck?
2. Neck shape - U or V?
3. String retainer - 'butterfly' or 'round'?
4. Code letter on base of pickups?
A TST would have a '50' sticker (usually gets lost), a U-shape neck, a butterfly string retainer and a 'U' stamped on the base of the pickups. Its a 58 Strat replica.
Go to http://www.tokairegistry.com and look on the 'Guitar' and 'Catalogs' pages to confirm.
James