So, how long has your mother been a client?
I would have thought mortgaging the property might be the answer.
I would bill him for the work carried out. He was fully aware that you were compiling the Accounts as he answered queries did he not. I would also quote him for finalising and/or submitting etc. Did he actually say he had 'changed his mind' or 'I didn't ask you to do it'. Big difference there. I would then sue if he doesn't pay. I had this situation recently and they paid up no problem.
I think I've got that letter here somewhere, should I have forwarded it?
He's probably a Shadow Director, unless he only works nights.
We had a similar case recently (1 large contract not to be repeated) and exception was granted. The delay was about 15 months. Given the evidence I would go (a). The Accounts can be amended later if incorrect I presume.
This sounds like the old 'no tax due on dividend payments so no Tax Return due' scenario common for directors' wives/partners. If so point out there was no legal requirement and they are mistaken. You may need to dig your heels in. Has been covered on AWeb before.
Request copies of the signed Share Transfer Documents. They will either be non-existent or have forged signatures. You will then know the course of action to take.
Plan B. You say 'if England win the World Cup I'll claim it'. Job done!
Do the Accounts including the claim but don't submit. Send an invoice with an additional item for hotel stay. He calls and asks what it is. You say I took a few days away while I thought about it. He says 'you can't do that'! You say 'there you go!