A Lawrence 79D 601 would be their "Gunslinger II" model. The holster was popular during the fast draw craze and is leather lined & reinforced in such a way as to allow cylinder rotation when cocking while still in the holster ( ! )
Available in black or oil finish. It should have a rawhide tie down thong and hammer thong and is designed to be worn low, on a buscadero style cartridge belt. The size 601 will fit a Ruger 7 1/2" .44 Magnum Super Blackhawk.
That style is not too popular these days but Lawrence is a premium name and they are long out of business.

I don't want to post a link to any open auctions but if you check Gunbroker listings by seller lunker1999 you will find a similar model but made for a Ruger Single Six listed at $50.00