sl1200mk2 Hey Wayne, Welcome to the U Can Do thread. You have lots of questions. I'm sure there are lots of guys here that will help out. I think the 91 should work fine for the Do. I wouldn't even consider a 72 for it, maybe for something else. There's guys on here that use the 100 on the 46. Also the 15% you have should be fine.
I've never used pinned hinges but have had real good luck with CA hinges. I've heard that you can install pinned hinges with toothpick through them to keep them from pulling out. Let us know if there's other info you need.