I bought an SRM OPRV several years ago and it seized open, so I threw it into the bottom draw of my tool box and fitted a standard one, and SRM's uprated oil pump. Couple of months ago I dug SRM's stainless OPRV out, and tried to free the piston. It took ages and the body was scored. I cleaned it all up, but somehow when putting it back together the spring damaged itself., started unwinding the coil spring. Rang up SRM, told them the story and they said send it back and we'll fix it and pressure test it, which they did, send it back FOC. Seems OK at the moment, and 10/10 for customer service. I've got a pressure gauge fitted to the bike to keep an eye on, but SS piston and body is not really a good idea.