Search real hard on here as someone had a press he was trying to sell. I believe he was on the east coast. He was moving and not wanting to take the press with him. It was all setup to use as a clicker.
That picture above is a bit used to lace rubber belting. Look for them from someone that sales conveyer belts. You should be able to get them 1/4" - 3/8"
1- make sure your air pressure is not too high 12-16 psi
2- are you letting your leather dry after your last application?
I would bet you drying it out before hitting the leather with too high of air pressure.
I use a new 5 gallon bucket with some gamma lid
( that's a screw on lid.) I leave it loose. Gets low add another gallon of vinegar and steel wool. Keep it under my bench which is living temp of the house. When do you guys rinse and neutralize the conversion dip?
I can't believe that you haven't found them rivets yet. I have bought the for Tandy the last time. Also bought domed rivet setters 4 mm through 12 mm. I believe they are also sold as mushroom rivets. Did you find anything o. Gold Star Tools?
Amazon you can get complete kits knock offs of iwata now Master brand ,including compressor ,airbrush $70-$80 bucks. If your not going to detail much get the brush with .08 needle.this is a gravity feed brush. Works great.
Why put anything? The scabbard I prefer when on a horse is unlined. It seems any lining in time starts catching a hold of sights or scopes when using linings. Just my 2 cents.