I had an L1 for a long time before I gave it away and got myself a 6PL (and a Fenix P2D Q5 is on the way =).
Anyways, the BEST holster I ever found for the L1 was made by AKJ ConcealCo (look them up on google). They make some concealment firearms holsters but they also make a great line of flashlight holsters in leather. There is no snap or velcro... they are "open top" holsters with good tight leather tension and a little adjustable tension device. I have NEVER had the L1 fall out. Plus, even though the 6PL was a bit too big for it, I used an old leather-worker's trick and soaked the holster in water for 5 minutes, then covered the 6PL in thin plastic (baggie) and jammed it into the holster and let it dry... now my 6PL fits the holster and it's still the greatest holster I ever used.
And, I've tried others (the SF velcro ones, the SF plastic one, and some home-made jobs from old leatherman cases, etc.).
The price is decent too, but the guy makes them himself and makes them to order, so you may wait QUITE a while to get it.
EDIT:
QUITE a while means one or two weeks up to a month depending on how backed up he is, though I think a month is generally the exception, not the rule.
Also, the holsters come in various sizes (75, 87, 100, etc.) where the number represents the diameter in inches (like .75, .87, 1.0) of flashlight that will fit. He also has a chart showing which types of surefires and some other brands (mag, innova) will fit bezel up and bezel down in the various holsters.