The Vanguard boats have metal backer plates bonded to the hull with fiberglass strips. Go easy putting the screws back in, the plate metal is softer than the stainless screws and it is possible to strip out the backer plate. If that happens, you might get one shot at bumping up one screw size and tapping a new hole.
Now would be a good time to do an air leak test, find the leaks and fix them before she's all pretty. Check out our videos on youtube, there are several on air leak tests.??
There is a nice search function on our youtube videos. Click subscribe and you'll get a notification when we upload something new. We also have a blog with a search window, and you can subscribe to that as well for email notifications. Scroll down the right side a bit and enter an email address.?
The important thing on air leak tests is to use low volume, low pressure air. Too much air can balloon the hull and pop the deck loose from the blocks, you would be doing an inspection port for sure in that case.
Cheers!
Clark and Skipper
Sunfish_Sailor Group Owners