Sir George,
"The law of diminishing returns" is rather apt. I tended to find that satisfied customers were generally
good for business.
Regards Bulldogs on the UK reg I believe there are circa 61 of which have a requirement for a CofA I am not sure but not difficult to establish. In context there are 122 Chipmunks on the UK reg and 175 Tiger Moth types which puts the Bulldog fleet into perspective but also the revenue potential of some of the types covered by DHSL.
There is a Bulldog owners section as part of the Pup owners club. Despite the relatively low numbers of Bulldogs it's an aircraft that a lot of people have an affection for having been used for many years as the basic RAF training aircraft and generates a lot of interest from past and present pilots.
VBR SB