The HIN on SeaCrafts is typically stamped on the Transom (starboard side). If your boat is a 1969 it would NOT have a HIN from the factory. It should have a MSZ#. Thats should be the HIN assigned from MA to the person who previously registered the older boat. The MSZ is a generic HIN foro old boats. Is there a MSZ # stciker anywhere on the boat? They should have given the previous owenr one to apply to that great old boat you have there.
Can you say red tape? Welcome to MA! Just need a sharp knife to cut thru it all
FYI
My 1970 SeaCraft had an MSZ#
My 1974 SeaCraft has a HIN stamp.