I've bought this old windsurfer but am interested in knowing what brand this is

i don't have the mast foot and will eith make something, buy one if someone has one or just flog off as a SUP. It's well made, appears to be Fibreglass not epoxy quite heavy but a production board not a custom for the 70's. One owner, parents bought it in nsw somewhere, possibly around Lake Macquarie newcastle for their son Who said it was one design brand.? Boom plastic ends have the number TK508B and TK503B. Centreboard and fin box have a similar number starting with TK - 103 and 303?