The Lymans weren't that bad were they?!After all, John B. George used one in the South Pacific with some success....maybe he was lucky!
As we all know, they were scraping the barrel for scopes in 1940/41, even considered that horrible Weaver didn't they? Clive Law mentions how Lyman's production was held up at one point by a lack of suitable sewing needles to use as reticule posts.
I can't say whether the Lymans were actually in use, or just in stores, but for some odd reason they show up in a 1980s dated workshop manual for the No4 Rifle. But, I have the impression that manual reflects a real 'generation-gap' in the knowledge of the No4. Or it could be just that it was written by some DND drones who never actually laid hands on a rifle since basic training.
Speaking of No53s, do we know what company used the diamond shaped trade mark with "WRP" or who "R.S.A." was?