Thought I might contribute a couple of general-purpose techniques that occurred to me & found really useful. They’re both sort of in the ‘duh’ category.
Need to measure something within a tight confined space? Scan & print a ruler & (after making absolutely sure it is a 1:1 reproduction) cut it to whatever length you want. You can glue it to a basswood stick & place it wherever.
I can’t believe I hadn’t thought of this before. If there’s a tough-to-reach spot in the hull, or if you’re just sick of having to grip the sandpaper for a long tedious job, just superglue a small piece of sandpaper to your finger and go crazy. The superglue’s basically harmless and wears off eventually with the skin’s own oils.