I have a flat black z61 clicky, but that's not what you're seeking.
I, too, prefer the z52/z54 LOTC twisties. And it is disturbing how much even the "common" HA z52 cost these days. I don't understand how the inflation of the old parts benefits Surefire, because if they wanted to, Surefire could obliterate that market by simply producing supply for demand. And I suspect these parts are not rare, just hoarded (well, the piece you're looking for sounds like unobtanium, my condolences). Just boils my blood that someone wants $65 for something they probably got for free as a warranty replacement from Surefire, that probably cost Surefire $15 to produce (after development was paid for, probably more like $5, or less). We are being taken advantage of; eBay sellers, at least, are preying on our desire for innocent distraction. And the Elite heads, omg, I will never be able to purchase another SF. It's Malkoff Devices and Lumens Factory parts for me from here on out. At least I got what I got when I did, just wish my interest had started about 14 years earlier, when E Series first appeared, and I was rolling in dough.
Now patents have expired, why aren't these pieces being counterfeited more widely? If a counterfeit is identical materials and appearance, then I just don't care it's a counterfeit, because Surefire no longer produces, so it isn't hurting their bottom line, the morality of it is less of a concern. I guess machinists are making too much money now to be bothered with it.