There's a place half a block north of Broadway and Belleview called Rocky Mountain Tanners. I drive by it every day. I'll get the address for you later.
4965 S. Broadway, Englewood, CO, 80113
303-293-2882
I'll suggest Twin Peaks Leather on Olde Wadsworth in Arvada (5655 Olde Wadsworth Blvd, Arvada, CO 80002). They did a great job restoring/repairing an old jacket for me, and they have a great selection of other gear.