Joslin Inst did a medical survey of their Golden Oldies to find out who still produced insulin and who didn't - it was about 40% did and the rest didn't. The GOs used to congregate every 10 years from all over America, in Boston with their nearest and dearest and whilst the Ds were having tests - they'd be ferried around on all sorts of expeditions - all paid for by Joslin! He (Eliot Joslin) was a great diabetes benefactor so was able to discover/prove all sorts of things that advanced medical knowledge about D.
Richard 157 is or was one of those T1s, who used to tell us about such things, didn't produce. He was well into his 70s at that time and appeared again a couple of years later saying he wouldn't be posting in the UK again.
As you say it's of no immediate help to either eg Sue or eg me, knowing that she's likely to be one sort and me the other at the moment - however it may prove to be for people like us in future from others using the research to find out other things or invent something that can help.