The fuel pump is a good place to start. I would also check (or just replace if they are old) all the fuel lines with modern tubing. My 1978 Black Max was bogging terribly and fuel lines were probably older than me (and I ain't young!). The inner lining of the older lines can break down and cause...
Following this thread with great interest! I just inherited an old Checkmate from my dad and there is a leak on the front keel very similar to yours (see pics). I was hoping to be able to patch it myself and with the help of this forum and this thread I think I'll give it a shot. I hope you will...