My PS3 is working again this morning.4
I'd say it's worth using your resources for a second holster. I did it and as long as you have guns with two different types of ammo (I have the handgun and the revolver) he'll automatically switch to the gun in the second holster when the first one runs out of ammo.
I was wondering if that's what happens. I need to find another one of those work benches so I can make some upgrades.