I wanted to upgrade Riton MPRD 2 red dot that came on my Ruger Mark IV 22/45 lite 43948. I removed removed the Riton and tried to install the Holosun 507k but it was not compatible with the pre-installed plate. Both Riton and Holosun states that their red dot are RMSc compatible. I removed the plate thinking they might be a dovetail underneath but unfortunately there was not. Can someone please help me find a plate that is compatible with this model Mark IV