The AC system was very recently regassed which spurred me on to replace the fan
While in for its MOT a few weeks ago, my friend at the garage asked me if the AC worked. I told him that it didn't and that I wasn't sure if the failed fan had perhaps lead to compressor damage.
He kindly hooked it up to be pressure tested and regassed and low and behold... when engaging the AC, the compressor kicked in and vents blew cold.
While I waited for the fan to arrive, I've tried the AC a couple of times briefly when moving just to check that the system is holding gas and all seems ok.
All I can say is... bring on the heatwave!