Well, not bad. I put an ethernet cable around the study reaching out to the radio, plonked a cheap USB sound card and the Pi, with my old USB to Serial adapter into it and voila, it works with VNC quite well, CAT and the lot. There are future experiments to be made, like using something faster than VNC but it works, apart from 6m. At 6m the cables are getting interference and the TX'ed signal is horrible. Needs more investigation. Other thing to look into is the audio cables, right now they are electrically connected. That needs to go, all of that cable stuff needs to be replaced with the audio/TTL connection kit I'm working on. That'd give me both octo-couplers for the serial side and also audio transformers on the other side. Anyway, we'll get there.
It's hard to see but there's a 9-band HF/VHF/UHF antenna tied to the back of the bike. In the end I didn't use this, just used a 2/70cm dual bander, that worked well too. Then on Sunday's ride we chained Ms B's bike onto a rail and then I realised I left the keys at home - 70 miles away. That was my day on the bank holiday Monday.
Finally obtained my full UK license - it's an M0. Unfortunately I had to surrender the M1 but I guess I could have insisted on doing it on paper and re-obtain that, I've been using it for a long time now, but hey, I like my new callsign. All I have to do now is remember how to say it.