Hey there! I’m in the middle of my build and can’t find a mast clamp that fits the Armstrong 72 mast. There’s a taper in it that is very tricky to model and my skills aren’t there yet 
Does anyone have an .stl or suggestions on how to do it?
Adapt the Gong V2 Clamp?
I made a STEP of an Armstrong 85cm mast, using a photo scanning technique, but if should be pretty close to the 72. It was mainly up a round the top of the mast for a foil assist. PM me you email and I’ll send it to you.
I guess you solved it already but what you can do is to put some layers of glass fibre on the mast after treating it with release film and build up the clamp from that, either directly with foam or make a 3d print model with the top and bottom section profiles from the glass fibre. I think all cad programs will have multi-profile section solid modelling commands.