Want to mount a rmr on my m92 pistol. But would really like to maintain a co witness through the rmr
with the irons. What are my options?
text is fine too 828-312-4716

I can't help with what will work, but I can tell you that anything that requires a picatinny mount will most likely be too high to co-witness. I believe your only shot will be an upper handguard that an RMR can mount directly to.

I have the StormWerkz mount on both my M85/M92 which I used to mount a Vortex Venom and Burris FastFire 3 and allows a co-witness:

http://stormwerkz.com/scope-mounts/yugoslavian-m92m85-scope-mount-fastfire/

These pistols don't have the traditional leaf system which the Attero Arms mount, which fits the RMR, fits nicely:

https://www.atteroarms.com/?shopp_product=rmr-mount

How well does it hold zero?

So far so good!  I don't beat the snot outta my stuff like RobSki does but considering their intended use I'm quite happy with them on both the M85/M92.  They have hinged dust covers so they effectively work like the Texas Weapons System railed cover which I use on another of my AKs, and likewise have no issues with it maintaining zero within the margin of the gun, ammo and most importantly, operator headspace and timing.  For CQB distances to 150m+ I can hammer a scaled IPSC chest plate all day.

Installed the Rapidfiretek rail on my M92.  The screws hit the carrier slightly. I'm not happy with that.  They will send me some shorter ones, but now I have to wait yet another week to get this build up.