Starter motor was swapped with loads of help from my mate. It was a slightly hassley job but not too bad in the scheme of things.
Battery reconnected, key turned............ a very faint click from the rear end but no roaring into life as we were anticipating.
Battery was good, it was fully charged and ready to go.
The starter motor that came with the car was used but presumed good.
Just wondering as to alternative issues, perhaps broken earth strap. Just got to work out where that is lol.
Bit disappointed but will be investigated further. Any other ideas?