Butch - interesting and valuable comments as always
I went to an engine and tractor show a while back where there were several CSs running. One was just beautiful. It was in "working clothes" finish, worn green paint, some bare metal, oil stains, but it ran as smooth and knock-free and clean and sweet and gentle and quiet as any diesel I have ever seem. No rocker cover, just the "sparrow filter" air intake and pepperpot exhaust - but head and shoulders above any of the others there for build quality. I never found the owner, I would have liked to talk to him
I think that the sweet, quiet, gentle quality of their power delivery is the source of the fascination with them. That and the (possibly unique) combination of exquisitely simple design and build quality allied to a simplicity of maintenance designed to suit anyone who can weild a spanner and apply common sense
Just my $0.02 on the appeal