Thanks guys. Those are actually screws with finishing washers and backed by slotted posts. I get most all of my holster making stuff from holstersmith.com. Good prices and fast delivery. Shipping is free with an order of $49 or more. It's also the only place I've found that sells some of the stuff, expecially the .375 x .225" flat head screws you need to anchor the male side of "Pull the Dot" snaps. Anything with a bigger head actually spreads out the rim of the snap and makes them even harder to snap on and off.
Funny you should mention Garrett Colonel. I've been lusting after one of their STX in Neptune Blue with a black lining, and that's why I finally took the plunge to do this. I didn't actually need another holster for this gun, or my P229 SAS that also fits in this so it was hard to justify spending $148 plus shipping for one of theirs, which is what it would have been for the Neptune and black lining add-ons. Mine isn't nearly as nice as theirs of course, but it is flat-backed which makes them so much more comfortable than most others that are shaped to match the back side of the gun. And that holds true for OWB as well as IWB, at least on my weird body type.
I set up to do all of this quite awhile back but never could get up the courage to actually try it. I used .080 kydex on this one and it's the last sheet I had left that was that thick. The toaster oven I bought at goodwill wasn't big enough to hold it so I stunk up my wife's kitchen using her oven. I didn't leave it in quite long enough (only about 4 minutes), so even my homemade kydex press couldn't press it down quite far enough. I had to do additional shaping in the garage with my heat gun. I don't have an infrared thermometer so I couldn't be sure it was pliable enough in the oven before setting in the press. Plus I actually used my P229 as a mold, covered with the goatskin and then some aluminum foil. The gun was no worse for wear after but I was still nervous about it.
I've made leather backed holsters before but not as nice as this, and always before using pre-made shells I bought online. We learn by doing and so I was pleased at the way this one turned out for the most part. One of these days I need to pick up some leather working tools, like a good skyving knife and a burnisher. My wooden sewing thread spool threaded onto a bolt and turned by my drill motor works pretty well to burnish but I can't replicate the nice rounded edges of a quality holster yet.
Oh, and for filing under the heading of "Who Knew", I recently read or saw something about clear skateboard tape. Can't remember where but because I was looking to do something in the way of a front strap for my Tisas Carry and didn't want to pay the ~$15 for a Wilson stick on front strap I decided to give the skateboard tape a try. I am very impressed with this stuff and will be using it for others as well. I paid about $9 for a sheet that's 9" x 33" so I'll gave enough for a few guns since the piece I used was only 2-1/6" x 1-1/4". And it feels great in hand. I used a piece of rubbery marine step tape on my Colt but I may just pull it off and try a piece of this instead. It might look as nice, or possibly better on a black frame.