Hi again Dave, I think this engine may be a later addition to your Scotty, if we could work out its date of manufacture we would have a good idea....however, I don't know how to date Tecumseh's....perhaps another member of the forum will.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl