There's a guy in Metairie that will mill and tap your slide specifically to your optic. He builds 1911's also I just cannot think of his name. Met him at a plate match and a lot of guys recommended him.
BTW, the Zev fits the RMR so tight, that you literally have to tap it with something to get it in/out.
Is his name Joey? My father is friends with a guy that builds 1911's and shoots competitions (or used to) and I think he was from Metairie.