Valuation of bare ownership / usufruct

Please could I enquire whether anyone can value / has a contact who can value the two interests created by a usufruct (and indeed whether this is needed)?

I have received an enquiry where the Usufruct was created by father (bare ownership went to daughter at that time) in 2016, retaining the right to occupy for him and then his wife. both father and mother have now died.

I have read Peter Harris’s helpful comments about the existence of article 669. The property in question was recently sold for £150k so there may be a question over whether a formal actuarial valuation is economic, and whether instead we can use the approximated values imposed by French law?

Many thanks in advance.