Ik have a clamp from amati but the wilhelm is to big and heavy for it. What is a good clamp ? Stable, turnable maybe almost upside down and good for big ships.
make bulding base board , put it on a lazy susan rotator. to work on flipped side use dowel in mast postions inbase board to hold in place.
Amat make a BIG clamp as wee as a small one. The big one held the SA which is 1m long.
I searched for a clamp when I started to build my 1799 Enterprise kit. I thought I could build what I needed. So far I’m satisfied with what I constructed. I think page 3 or page 4 of my Enterprise thread lists the materials that I used.