I compete with and carry a Glock, which is hardly a work of delicate art. l'lI give you my impressions of your design from a modern perspective.
We cover our muzzles for a couple reasons: Protect the crown of the barrel for accuracy and the front sight from getting ripped off. Protect our furniture. To some degree to hide what we are carrying.
Most people who have bikini holsters use them for range use where they will be shooting multiple guns and just want to put on one holster that will fit all of their guns.
Up and down from 3 o'clock is the fastest position to get on target from. In fact, a person could shoot at the target immediately after clearing the holster (speed rock style). Cross draws, Small of the back, etc. require swinging your gun to the target. The swinging means less control of where it stops and allows your attacker time to grab it.
I'm a firm believer that Murphy was an optimist and as a result I could see enough of the rivets busting that the wearer would lose control of the pistol, either the belt loop or the holster falling apart. Alot of kydex holster suffer from the same vulnerabilities.
Since you don't like sewing, you should consider linking up with some of the holster makers here to see they'd be willing to enter into a consignment type or wholesale arrangement. I'd bet you'd sell more replicas if they were packaged with period-correct holsters. The holster is the frame that should complement the pistol.