Interesting survey Dick! It seems to confirm the location of Antony Dannecker's Official Repair, Sales & Service Centre Based in the UK. However it does not shed any light on Bernard's claim:
"Like it or not, it works AND is standard practice".
If by any chance someone is curious about that there are a few riddles to sort out still like : What works? How does it work? and How is the standard defined,established and documented?
Well - I am not all that curious myself, I remain having no illusions that *this* "works":
"make the lower pitched bass reeds a few cents sharp so that they blow into tune"
Sorry Bernard...!