Beware of the Long Firm Game
https://www.gov.uk/options-if-youre-owed-money
The Small Claims takes nine months (my one experience) or so and I think it works better with headed notepaper from a solicitor. I got my dosh this way but it was more hassle than the £1200 (£5000 now) was worth...
Masked and Anonymous
I would tend to put more pressure on him to collect the debt before the other creditors and try take what you can get (say £1000) before he goes bankrupt an you will get next to nothing.