I am looking for a Streamlight Stinger holster that has an open top. If it has an open bottom, that is fine, but not required. I want it to have a flap with either a snap or Verlcro. I think they exist. Who makes them and where may I buy one?
Something like that with a flap? Best bet might be to track down a leather worker with experience on Etsy and commission him to make you one. Type: Leather flashlight holster, into the Search bar. Then scroll down a bit.
No flap, but JG5sleather has an open-top and bottom leather holster for a Streamlight Stinger on their Etsy shop. Full disclosure, I've never bought from them before. But perhaps that holster is ideal for your needs?
Googling I saw a few button top leather ones from $25 - $50 (some bottom closed some open) and a bunch of "no-name" nylon button or velcro open bottom or closed ones from $8 - $15 both styles claim to be made for the SL Stinger.
Flashlight/battery sites and sporting goods sites seem to have them.