Hi, original poster here!
Firstly I'd like to thank people for their helpful replies and offer my apologies for not getting in contact with Paul and Will last year despite their generous offers. My planned passenger had a sudden and unexpected change in his circumstances, then covid happened which had big effects on us both, workwise, pretty much reducing our free time to nothing.
Anyway, it has given me time to workout what I want to do! Though I'm not sure it is possible.
I'd like a twinshock or possibly even pre'65 bike that I can ride solo or with a chair. I'd like the flexibility so that I am not reliant on someone else all the time.
I'd really like a TY175, mainly because I had a TY50 road bike as a 16 year old and there was a 175 on the cover of the manual which I lusted after! I like older machines in general and still think TYs they look nice today. I also read that they are good for beginners and reliable. One of my classic competition cars wasn't reliable and it was miserable trying to fix it inside a week as I needed it again the next weekend and constantly being worried that it would break when I should have been enjoying the event.
My passenger and are both short (I'm the tallest at 5'6!) and light (sub 11 stone) but I think we'd still be too heavy for a 175, wouldn't we? So might need something bigger.
I've got an Yamaha XT500 road bike which I have decided to sell or part exchange on the trials bike. It was running when I parked it in the garage (10 years ago) and I've had it running on easy start so my next step is to get it running, MOT'd and sold. It will make a good project for someone else. Then I'll know how much I've got to spend on the trials bike / combination.
I'll aim to find something reliable and suitable for beginners both as solo and combination. I guess I'll aim for one with the sidecar already attached, just because its easier to work from a set up that has already been developed.
I would have thought it will be a long time before the thing holding our results back is the machine, rather than our lack of ability.
Am I on the right lines or going down a rabbit hole?