Mr_Happyface

Gents, I bought a Benelli M1 Super 90 a bunch of years ago, it was the first thing I bought when I turned 18. I love this thing. The rear sight has always required a substantial amount of windage for the gun to be zeroed though. I suspect the front sight is a little crooked, nothing I can do about it though, it's fixed in place. I bought an RMR and I'm looking to mount it. I'm aware of the Scalarworks mount, but I'm looking for something that doesn't require the receiver to be drilled / tapped. I've been searching like crazy but can't find a mount or rail that REPLACES the rear sight, there's already a few holes tapped so I'd like to use them rather than drill new ones. Not interested in co-witnessing since the sight is crooked. Has anyone seen something like this? How has it not been made yet?