Hi,
My Grandfather inherited money in a similar way, the estate was over £60000 but there were at least 8 beneficiaries. The probate research has company (Fraser&Fraser of Heyr Hunters fame) charged about 30%. Think each person inherited £1500-£4000. I think what you have explained is pretty standard practice. I would imagine that as you say the soliticitor has instructed the company. I think estates only crop up on the bona vacantia list when they have very little information to go on (no listed nok, unconfirmed dob, no docs in house)