Hi Guy. Thanks for asking.
It's not been plain sailing but I think it's alright.
Fermentation looked to have started the next day (I peeked and saw the beginnings of some krausen) but the airlock wasn't bubbling. This was the case for a good few days so I decided to investigate further. The lid had unclipped from part of the rim, to let out the CO2 that couldn't escape from the blocked airlock

, I removed cleaned and replaced the airlock and firmly closed the lid all round....the airlock bubbled! It's now getting on for a fortnight (on Monday in fact) and there doesn't appear to be any more bubbling. I shall leave it until Monday and if I don't see any sign of bubbling I will have a look in the fermenter to see if it looks like it's finished, if so I shall test the SG and go from there.

all is ok!