Server switch-off
It has not been possible, so far, to find a server capable of hosting the site as the software is old and cannot be upgraded without purchasing a licence from Invision for their current forum platform.
Whilst this site is no longer being used, it does contain a lot of historic content which I'm sure is of interest, and I will keep looking for solutions to make this available. A full backup has been taken.
For now though, this site will go offline when the server is switched off on Monday.