Hello,
I see you (or someone) posted this to a Colt Forum 10 yrs ago (same picture shows up for a Google search). Jerry Burney here would be the final arbiter for this subject.
I like cool things. Since I can't afford originals, I look for repros.
CMR Militaria sells some of the best I've seen. Some things are "Fantasy" pieces, .... like the leather snail drum carrier that was ???
CMR used to offer this, they called it a Tanker Holster. I still have it in the safe with a repro bronze Panzer medallion affixed between the holster and mag carrier;
https://www.zib-militaria.de/WH-shou...-black-leather
Probably custom made for someone if it's not adjustable for size or bulky clothing.