First, tell me where you got it?
I suspect, if the word Cobra was attached, then it is just a "Cobra". The Flex and Warp were names applied to the first two models (by Jim Gaska and/or Travis Whitney). The Cobra was a gun similar to the others (aluminum frame), but with the Cobra valve snd larger transfer port. I owned one of the few Cobra models sold, and literally gave it away. I know what happened to that Cobra, hence the question I ask.
The regulator does have creep and will have, as long as you fill the gun to 4,500 PSI, and you don't adjust the regulator under pressure! Over the life time of the regulator, there were several different materials used for the valve seal. If you actually own the WAR I once owned, you have the latest material. If the regulator isn't working at all, it is the o-rings, not the seat itself. The tiny ones are #0s, but I don't remember the others. I used the same ones the .25 breach used. But again, the regulator does creep overnight, and you won't fix it!
Jim Gaska still has some parts available. However, he has a very difficult job, requiring long weeks and nights. If you do email him, expect to wait. If you have other questions, ask away!