Ok my home renovations “ should be” coming to an end in the next 2-3 weeks. Just in time for the good weather. I’m going to be taking my 64 merc out. The wife wants me to install seat belts. She’s quite adamant on shoulder belts front and rear. I’ve installed them in my 50 Chevy relatively easy. But! How do you install shoulder belts when you don’t have a roof or sail panels ?