Thanks, Julian and Matt. Yes, a relative contacted me per Ian's advance wishes. I am getting of an age when many of my friends are passing and I have asked them to have relatives let me know if "something" happens. The nature of online correspondence is often one-to-one and even with continued contact, you sometimes don't know why communication abruptly stops. There have been losses due to accident and illness where I didn't find out till much later...or with sensitivity to family sometimes at all, except for a check of death notices. Thankfully Ian took measures to notify while easing the burden on his survivors in his typically thorough way. I've learned a lesson here myself.
I take care to respect members' privacy here so tend not to use last names unless they did in open correspondence. Since Ian mentioned his location in the bike sale thread, yes he was UK-based, just northeast of the Midlands.
I will make sure his family sees the good wishes left for him. A local memorial will be held after the first of the new year. I'm sure there will be lots to work out.
Best, Dan.