I think you're dead right Matt that the Webley's such a neat, compact, efficient design that it deterred and out-competed anyone who thought about trying to squeeze into the market. I guess German air pistols in the '30s only succeeded in getting a toehold in the UK market because importers were able to undercut Webley on price and meanwhile the makers could rely on their home market to provide baseline income.

I also agree the FWB65 was the postwar equivalent of unassailable market leader in the late late '60s and '70s that left only scraps for rivals and probably deterred some companies from entering the match spring pistol market altogether - Anschutz for instance.