Re-reading your email I finally understand that you were talking about all seams, not just the deck-to-hull one. In that case I think you are over-engineering the project. Usually S&G builds use interior stations to help support the shape while the filleting and glassing takes place. These stations are on the inside and should be enough to fillet the inside seams and glass the outsides. The more stations the better, on my last boat I used 7. Then you can take the stations out, glass the insides and join the deck and hull. If necessary stitch them together the way I described, you may be able to get away with tape.

I'm still not sure what you mean by guides and brackets and also if you are using interior stations, which is standard, or not but it sounds as if you want to use external stations. That should work too but it sounds like more work than internal stations, which is common with S&G and that usually work well enough.

Henk