I have a 39 Tula ex-sniper coming Tuesday and I ordered Igors repro PEM mount a couple days ago off ebay. Thats the only PEM side mount I know of. Side note-Igors is for low wall receivers and most side mount exPEMs are high walled (I think). My 39 is a "CN" marked Tula but it is on a low wall receiver and was never drilled/tapped for a mount.