Oh, believe me, I've explored a huge number of options using various combinations of materials, connection styles, hardware types, etc. My desk is littered with all manner of rings, snaps, hooks, swivels, and clips, along with various styles of strap adjusters and other webbing hardware. I think I've finally come up with something I like. When I get some time in the next couple of days to complete my assembly, I'll blog about it (and post here, as well).
But, the coating on the hook is really a minor concern. I think I'll accomplish that with plasti-dip. I wasn't ever particularly concerned with a hook scratching my balance hanger. Originally I was attaching the hook to a black powder-coated ring, and I wanted to avoid scratching the finish off that. But, I've moved on to another design entirely. I also sort of want a black hook to just match the rest of the strap.
The kicker has been finding something with a 90-degree twist between the side that attaches to the strap and the side that attaches to the bassoon. Without that, my bassoon doesn't hang properly and playing it is uncomfortable. I know this could be accomplished by adding another link between the hook and what it's attached to, but that's too clunky for my tastes. I've checked every hardware store in town plus plenty of online hardware stores and even places that specialize in materials for lanyards, straps, and the like. I couldn't find any hooks with the twist, regardless of size. I also checked things with swivels in the middle, but these were all either too big to fit through the balance hanger or too small/poorly made for me to trust them supporting my bassoon. I've ended up just bending a standard s-hook to the shape I need. I was a little concerned about this weakening the hook, but I've tested it to my satisfaction.
In any case, I'll show you guys the finished product soon.