Oh dear David, that is very sad news!!
I can only echo Ken's comments, he said it all!!
Only this afternoon, when I managed a brief look at the thread, I thought how Reg's input made such a difference and looked forward to his return from this latest break; alas now not to be, I/we really shall miss him greatly!
He was a friendly and knowledgeable participant in this and many other Prune Threads. (I think that you should consider posting your announcement in those too, but I expect you've already thought of that).
RIP Heikki, aka Reg, aka RegDep.