Thumpy, work with Silencer Shop if you can. Only one set of prints needs to be done. Will need your picture annually though. Also, be careful what associated dealer you go to. Their recommended dealer isn't as inexpensive as the LGS I use a couple of miles away from them.
Being a lefty, here's what I do shooting righty. Close my dominant eye when shooting a long gun. With a handgun, just use your dominant eye.
Because you have a damaged eye, shoot with your right eye closed. Only advice I can give you, other than try an optic.
Thumpy, Gary Paul Johnson wrote an article in which he claimed there could be a legitimate need for a belt-fed for law enforcement. I am not kidding; it was a review of an OOW M240.
Unless you can find 1. someone who wants a sample of every gun the Tennessee Highway Patrol has ever used, or 2. evidence it was used in a historical event, it's worth whatever an AR-18 of its transfer status is.
So if I want a .50, buy a rifle and ammo now?
Also, for M2s, I wonder about parts kit availability. Due to the war in Ukraine, I suspect folks are going to hold onto any source of spare parts they can.