An update - the front one......

The front one is skinner that the back and is consequently even stiffer. Rim has been thoroughly cleaned and polished internally.
1. 60 PSI, jell and bumpy road. This did the back tyre. Nope.
2. 80 PSI and more jell. Then bounced. Nope. This was done by remotely operating the pump before I was satisfied it wasn't going to go pop!
3. Local bike shop, big compressor and air tank - 95PSI and some really slippery tyre soap he keeps for such occasions. FOC, because he knows i'll be back for MOT again.
"Let's be careful out there"
