If you are happy with your purchase and they will give you enjoyment, then you didn’t overpay. Don’t worry about it. On the other hand, if you are thinking you can fix them up and sell them at a profit, that doesn’t happen very often. Hasn’t worked for me yet. martinoutboards.com will have your head gasket. It is a multi piece gasket and you have to replace all the pieces.
Your Gale Viking is a 5D10V and lots of them were made under various brand names. They are surprisingly good runners. Probably needs new coils though, unless they have already been replaced.