A while back a customer asked me about a sling for his Marlin 1893, it's a collectors piece so he doesn't want to drill it for sling swivels.  I told him that I'd2 try prototyping something on my Glenfield 36G to get a feel for the project.  Basically what I came up with is a lace on butt cuff with a brass square ring attached via copper rivet and a forend cuff with the same setup.  This allows any standard sling to be attached to the rifle.  It worked out pretty well but the forend cuff on this