Does 'stitched tape sling' in this context mean the way the tape was manufactured. I'd be amazed if it meant stitched as against knotted, in 1970. I notice the pink tape in your other photo is knotted. I'm sure I was still knotting slings in the mid eighties. Best of luck with your quest, by the way.

In the early seventies, Peck Climbing Equipment had gone in for stitched webbing sling for their Ny-Chock which gave a break strength in excess of 4,500 lbs. using their Gold Tape (Rocksport December 1972).

So you mean it was stitched like modern slings...? Wonder why it took anothe fifteen or so years to be catch on?

Plenty of stitched gear round in the 70's, etriers for a start