The most prolific writer of Westerns you've never heard of?

I read a couple of days ago that J. T. Edson, a very well-known (outside the USA) author of Westerns, has died.  His books were a big part of my younger days, and the news of his death brought back many memories of them.

Most Americans have never heard of J. T. Edson, being more familiar with Westerns by authors such as Louis L'Amour:  yet Edson wrote over 130 of his trademark short novels and sold tens of millions of copies of them.  He lived in Melton Mowbray in England, occasionally visiting the USA but never living here.  He was almost entirely devoid of any personal Western or associated background.  He once famously said, "I’ve never even been on a horse. I’ve seen those things, and they look highly dangerous at both ends and bloody uncomfortable in the middle."

Despite this seeming handicap, he immersed himself in Western movies from the 1950's onwards, and surrounded himself with replica firearms, research materials and the like.  At his peak he was publishing up to half a dozen novels every year.  Whilst they never sold in large quantities in the USA, they were extremely popular in England and several Commonwealth countries, including South Africa where I encountered them.  Along with Louis L'Amour's Westerns, Edson's books were common in military camps and similar settings, and I understand they were popular among British servicemen as well.  I can remember many nights spent reading two or three of his books, consuming them rapidly, many of them already familiar, then turning to another one to while away the hours spent on radio watch.  In due course the copies floating around military camps became so dirty and dog-eared that they probably represented a major health hazard;  yet they were still passed around until they fell apart at last.  I recall that one of his books, 'Apache Rampage', was a source of great frustration to me because several individual pages were missing from the only available copy when I first read it.  It took me several years to locate another, more complete copy and 'fill in the blanks' in my memory of the story.

Edson isn't the only non-American author to be a prolific producer of Westerns.  Fellow Englishman Terry Harknett has written well over a hundred under pseudonyms such as George G. Gilman (the 'Edge' and 'Adam Steele' series) and several others.  Again, I haven't often come across them in the USA, but they're very widely read overseas.  I'm living here now, and I've traveled widely across much of what was once the Old West;  so who knows?  Perhaps I'll try my hand at a Western series one of these days, just for the heck of it.  I must have read many hundreds of them in my time, and I'm not hampered by political correctness, so it might be a fun challenge.

Peter