Use Loctite® PL Premium® FAST GRAB Polyurethane Construction Adhesive... It works...
Sewing patches is ideal - especially when it's an historical repro. You want it down to the OD thread, yadda, yadda, yadda... BUT? Most places sew right through the jacket/vest. I've seen them sew right through an inside or outside pocket. The good ones remove the lining. They charge more than $10 - at least the ones I've worked with.
Flight Suits / G&B does it right. If that's what you want, give them a call.
For myself? The only one I've done myself is a Sons of Anarchy cut. I did it the way they do them for the show - Loctite® PL Premium® FAST GRAB Polyurethane Construction Adhesive. They tell me they got that "tip" from a couple Hell's Angles from Oakland.
On that note? "They" recommended getting repros from WizardPatch. LOL - Because FOX has locked down the IP on Sons, the only really identical repros come from these guys who make and ship from China. No sticky IP-related laws. The company is based in Australia...
Oh - the awl idea? I hope that's a joke. You really think that's how to sew on leather? Cut your steaks with an axe?