Seat belt refitted without to much trouble, helpful neighbour assistance was again utilised to manipulate two spanners at the same time and a cranked spanner as per Roady’s picture was a great help.
The bolt was a tad awkward to get back in, I dropped it and ended up having to take the tool tray out to recover it after that I put a duster in place to catch it if it dropped which it did several times. To get the nut on I put a bit of duct tape over the bolt so I didn’t push it out again while trying to get the thread started which seemed to work quite well.

It isn’t a five minute job and a few profanities were uttered along the way but it is doable.