A friend needs a good divorce advisor. Her ex-partner is a solicitor
himself and his law partner is advising him - and surprise, they can't
produce their partnerhip agreement - just one of the tricks!

Bottom line: She needs a strong advocate to counter these antics - how
best to find one please?

A five star answer needs a short list with links to strong evidence of
effectiveness.

A good backgrounder on the general circumstances and approaches will merit a tip.