After a quick search for a spare saddle and a few minutes tinkering my old Longstaff TWD was unleashed for a brief test ride and I can confirm that after many years on 2 wheels that I am still able to ride a trike. What is surprising was how natural it felt to be on 3 wheels again. I've never ridden a tandem trike and C. has never ridden a trike, but we both like a challenge.
Yep, I know about the Maillard issue, that's what's on my Longstaff and is one of the reasons it's been sat idle for so long. At some point I will need to assess the cost of refurbishment against the cost of a newer second hand machine, but I don't have the budget for either for the foreseeable future. If C. is on a bicycle then I couldn't keep up with her riding my trike and we would rather ride a tandem anyway (with either 2 or 3 wheels).
As for our tandem trike plans, we have to get one first and find out how well we get on with it. I expect that it will be great fun and that's all that matters. We like to start with modest goals and do as much or as little as we feel like and can fit in around other aspects of our lives. The PBP is on our wish list for next year, but unless we get lucky and find a suitable tandem trike that is affordable then it will be on 2 wheels.
Its a small world: it turns out that I knew tatanab >20 years ago and he is the former owner of my Longstaff - great to be in contact again.