boat cover hardware

I am going to be purchasing a custom canvas enclosures for my 345. I was wandering if anyone had any suggestions or tips on anything I should ask for per special request. Example: double stitch the whole thing, triple? 30 mil or 40mil? This is my first full canvas re-do without oem specs so I...

I have several of these round parts that have loops coming out of my boat cover that go around the parts. They are made of plastic and are so sun damaged that they are literally crumbling apart. This is the only one I could find that's intact. Do you know what these are called? I can't seem...