Hi Ron,
I am glad you enjoyed reading it. It was a lot of typing for a slow typist.
I wrote it off the top of my head, from information read and gleaned over many years. I was bored at work today and your thread inspired me to put it all down. I felt from the tone of your thread, that other people might be interested in reading it and maybe learn something from it. I did have to look up the exact years that each eyepiece design was first proposed, as my memory isn't quite that good.
I am happy for it to be reproduced, in whatever form anyone sees fit, with appropriate acknowledgement.
Clear Skies
John Bambury