I started with Watson and Sons (EM) Electro Medical that is in 1967 as a junior engineer in the Manchester Branch. I'm sure I serviced a Kingsway that had belonged to the RAMC dental dept.
A friend of mine remembers old watson units being crushed in Germany at the end of WW2. It was cheaper to crush them than bring them back. I did get a call to a Kingsway (Watsons original London address)that had lost all three counterwight cables and fallen down with a large clang, the cables were replaced and it carried on working for several years.
Mobilix 60 and 100 were the common machines of that time the 300 was a major x-ray set on wheels. That drive system was a pig to service. One of our local hospitals had 24 MX4s in the end, I spent weeks installing them. My portable which I use for checking my test gear is effectivley a dental unit in a small suitcase 68kV 15mA the only variable is time.I sit behind a desk these days but still miss the hands on.