I have some Vortex PMR 30mm low (0.87") rings that I would part with for the Seekins highs you have if the 0.87"/0.92" (I believe the med highs are 0.92") difference isn't too much for you. As the poster above stated, the Vortex PMRs are made by Seekins. If these are not too low and you're interested feel free to shoot me PM. Good luck.