When Doug first came out with the Mk1 he offered it along with the Bianchi Accumold 7303 Single Mag/Knife Pouch w/ snap closure, size #2, (or sized for Browning Hi-Power magazine clip).

Some folks complained that it had a loose fit, but I myself thought it fit well. I like the sheath.

Hint: Don't get the version with the velcro closure. I did - for my M2 Mk1 - and wished I hadn't.