Well, got the towbar fitted today, had to get the 'old fella' to come over with his angle grinder to remove the old bolts. Removing the rear bumper caused a bit of head scratching at first whilst I tried to work out how to remove the LPG filler.
What I did was split the glass pipe at a conveniently placed union

I had thought about trying to strip the filler down and remove it but changed my mind once I realised it was easier to split the union.
Once the towbar was fitted I spotted an issue with the route of the gas pipe, I had to reroute this which caused a bit more head scratching, only to suddenly realise after a good 30 mins thinking time that there was an easier solution. The problem was that the gas pipe was contacting the towbar.
I managed to run some tubing along the pipe creating a safe route. The towbar came with plugs fitted for easy connection, so rather than disconnect the cables at the socket or cut cables, I decided to make the hole in the boot floor bigger, necessitating a round the local car parts shop for a bigger grommet to run the wires through.
I also found that when I removed the rear mud flaps they were packed with dry mud, so those were cleaned out and reattached.
All in all a productive day, just hunting for a small trailer now.......