I haven't seen Peter for many years but we still exchange Christmas cards and have a chat from time to time.
I was privileged to have worked for Jim as Thameslink MD, then Cliff Perry who was our next MD, then Euan Cameron, then Keith Ludeman and finally Mark Causebrook. I last bumped into Cliff at the NRM at York a few years back. We once shared a taxi from our office to West Hampstead when there was some shambles in progress with the OHLE but instead of planning out possible train services we spent the time talking about potential improvements to his OO layout! I see Jim fairly regularly and also Mark, but haven't seen Euan or Keith for a long time.
You are certainly right about the loss of talent Ian, although quite a lot of them would reappear as consultants in due course!