I recommend two things here:
1. Look at the firm's Linkedin page and go through its 'posts' on Linkedin - here, you might have some press releases relating to recent deals / matters the firm has worked on, which would usually include disclosing the client in question.
2. Look at the profiles (on the firm website and Linkedin) of certain key partners at the firm. Here, you might also find 'selected representations' or Linkedin posts related to the work that that particular partner has done (be careful here regarding the representations on the firm website though, as these can sometimes relate to work that the partner did at a previous firm!)
Hope that helps

It is difficult when researching smaller firms as they aren't plastered all over the FT!