Surefire 7Z Alternative

I've been pining for a 7Z to host a Malkoff module in, but considering their status as collectibles, finding a user/beater 7Z is well-nigh impossible.

Would it be both possible and reasonably practical to turn down a KR2 extension to build a CombatGrip on the adapter? Surefire's been good to me about sending along extra consumables in warranty packages, and would probably send me some more rubber rings. Think it'd work, CPF?

(yes, I know li-ion works too, but the surefire ni-cd sticks have substantial run-flat tolerance, and are safe enough to loan to family. If AW made protected IMR cells, I'd standardize on them... but they don't, so I still need a variety of cells.)

Those 7Z do pop up on the Marketplace from time to time. Picked up a used 7Z while back for a good price. Maybe another one will pop up sometime.

I've been watching for those for years. I've seen a couple deals pop up, but only about two in the sort of price range I'm expecting for any other used Z series light.