Opssys, ah, the caps only typewriter for railways is so obvious I had not thought of it!
Incidently I have seen a photo of a telegram sent from Darwin reporting the Japanese bombing of the town in WWII. This typewriter had a very cunning font! It appears that the lower case character were so designed that they could be overtyped with their capital equivalent and still make a nice character. In that example you could see that all capitals were overtypes and I can only imagine that the morse telegraph operator copied it first in all lower case (is there a case signal in Morse? I dont think so) then went back and capitalized where required.
IIRC the US aircraft supporting Operation Deep Freeze in Antarctica had radio teletypes on board in the '60s.
I used to operate morse on aeronautical circuits, point to point though never air ground, and in 1999 I saw them still using it in Pyongyang.
There were some very good coding schemes in use including the grid winds which was a series of 5 figure groups and if you typed it up properly you could go over with a pen and create a nice weather map! I tried to write software to do it as one of my first PC programming exercises but the task was really beyond me. At about the same time (1970's) I made a morse keyboard using magnetic cores and about 20 first generation ICs, it worked really well but I found it confusing to use as I could type a word then hear it going out on the transmitter and my earlier training caused my fingers to type it again!
Thanks LTAfan I will study Dr Polt's page!