Hi Kevin
I recall a couple of pairs like that many years ago when I was a lad ( no many,many years ago!)
They were fairly low power binoculars and the description from my Mum was, I think, "opera glasses." That might tie in with your " jockey" marking as they could also be used at the races. Either way not in the same league as the light weight binoculars produced today – I had a pocket sized pair of Olympus 8×25 as a birthday gift from my youngest – amazing clarity! I guess, as in so many fields, all the processes have been mechanised and improved.
Norman