If you go to the Sears parts site(don't know the address.You may find year and part numbers.I can tell you it was built by Tanaka and is based on the TOB300.I believe there is a Tanaka site as well.
thx, did both before i posted...nothing...no dates.... was hoping someone might ahve another way to figure it out... i think probably 1996 or 1997...that a bunch for your response
