I found this buckle over at Tandy Leather. It looks very close to the Lee Keppler bagstrap buckle. For those of you wanting a more screen accurate bagstrap buckle or making your own bagstrap, this could be for you!
Hrm, looks good. I like the way it's not as fat as some, but it's a tad too wide. Too much of a rectangle, IMHO. In any case it's very good! Thanks for the link Dr. J!