Guess what I've done now!

Are the 12 volt fuses not somewhere near the power supply unit (main fuse/breaker box)?

Our Abbey freestyle was 2005 and had the main breakers in the wardrobe. However, unlike our current Bailey the 12 volt ones were not directly below. I seem to recall they were under the seating at the front of the van.

My Abbey fuses are front end under the bench - but there are trip switches in the long/tall/thin kitchen cupboard - where the aerial  and the table lives. 

Right then - been for a photographic crawl around. The pic with 12v skt and ignitions is in the overhead cupboard beside the ESM unit. Would that be it, are they fuses? The rest are taken under the seat near the battery box.

The pic with the 12 volt skt and ignitions looks favourite. Under the labels is a clear plastic cover. Are there blade type fuses below this. If so the 12 volt skt and ignitions would be the one to check. I assume your electric ignition on the cooker is also not working. I don't know if you carry any spare fuses but these can be sourced from Halfords or similar in the morning. 

I'd have thought bottom left looked the most favourable  

SteveL you are right about the gas ignition - it isn't working either. This is a pic with the cover removed. The bottom blue one looks a bit out of kilter - do you think that's the culprit?

Remove & check it.  

There are slight variations, but this gives you the gist .... https://www.google.co.uk/search?q=checking+car+fuses&client=tablet-android-samsung&prmd=sivn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiMuZ_Wo9_VAhXFKMAKHUhpDNMQ_AUIEigC&biw=1280&bih=800#imgrc=3O4ZrCASR9yjjM:

Given the labelling I would have assumed it was the top red one. However, as you say the bottom one does not seem to be seated properly. Can you see if the thin wire through the top one is intact, or broken?

Right again - I took the top one out and there was a break in the line across the bottom. So if I go to Halfords tomorrow and take that with me they should give me the correct replacement? What a way to spend a Thursday evening, still it keeps me off the streets ;-) Thanks again everyone for all your help, I feel I've ascended a bit more of "the learning curve" xxx