I think Ralph Steiner may very well not be with us anymore, but I stand to be corrected.
Far from being a dying breed, 124 on the UK register
GINFO Search Results Summary | Aircraft Register | Safety Regulation
We have 2 at Prestwick, used for ab-initio, aerobatics and tailwheel diffs. And we're not alone in the UK.
Ralph was a very, very useful contact though. Failing him, de Havilland Support is your best bet for info and contacts
de Havilland Support Ltd