First, thank you P, I'm glad you liked it!
About the strap, the only alternative I was informed of, 1 year ago, was the Kevlar strap. It is the kind of strap which was used with the original RM027 at first and, then, adapted to the RM035.
I don't think there are others and don't think it was compatible with the RM010.
The best thing is to ask a RM boutique, you'll be sure.
The Titanium RM030 is a really nice contender: nice skeletonized movement, with a little more room than the RM010's, nice declutchable rotor feature. Be careful, It is in the bigger size though.
I don't have any finish problem with my RM035.
It is a nice project you have!
Cheers, Mark