Yes thanks for that Pete
It's all a bit curious isn't it? I photocopied the instructions [with a photo] when I sold mine and these are also available on-line somewhere as well but there has never been much else around
I have a Nems Clarke VHF set re which there is some technical detail but very little general background info. It's quite high spec and I was a bit puzzled until I realised that they were used in the US sixties Space Program!
Dave W