Follow Up:
Thanks, WC, I had actually come across that thread in search of a holster. But, I decided that I really wanted a pocket holster that could fit in cargo type pants/shorts, bigger pockets and the small zip pocket in my gym-bag. The main things I wanted was 1) avoid the imprinting that you get when pocket carrying; and 2) keep it somewhat protected and secured; make sure that it could fit most pockets (other than jeans).
So, what I did was decide to take a chance on ordering one of those pocket holsters from Smyrna Shooters Supply. I chose the one molded for the Kel-Tec P-11. FWIW, I called ahead and tried to get some information about this holster and whether it would possibly fit the AMT Backup. The guy who answered the phone was pretty short with me, just said "we don't have one to fit your gun", with no suggestions and that was about it for the conversation.
I checked out the dimensions for both the P-11 and My AMT 45 Backup - they dimensions are very similar. I figured that if I needed to adjust the holster, then I could probably figure something out to get it to fit. If it turned out to be a total misfit, well, I'm out some money, but figured it was worth the gamble. I
I received the pocket holster a couple days ago. The holster is actually nicely made. It's a near perfect fit! Really, no adjustment is required at all. I'm debating on whether to trim the top and the side of the flat piece of leather (prevents imprinting) by about 1/8th inch. It fits nicely in the pockets, as is, but maybe could benifit from a slight trim.....maybe. I'll have to post some pictures for anyone interested.
It's a shame that the makers of this pocket holster really don't know what "other guns" their holsters can fit, nor do they seem to care much. But, for any of those folks who have an AMT .45 backup that are looking for holster possiblities, this one fits nearly perfect.