Hi JA,
Yes exactly like that.
I to thought of a something like a hose clamp or an over center clamp, but that would be too bulky, would look kind of unsightly and would need another tool to operate
So, yeah I recon something like in your photo would do the trick, it would easy enough to manufacture, be made to look aesthetic and easy to use.
I'm actualy going to make the clamp integral to the outer rotation threaded ring.
Cheers
Josh