basically that's it unless you use bl's index as a base and then check the new index when you can't find the will (you will of course miss the non or mis-indexed wills this way) - there is another card list of wills that also mentions people in the will but not computerised and not that convenient to search.

I understand that MNH hope to open a fam history annex sometime next year (funding permitting but this may be harder to justify now) - the museum library must be the last major library in the british isles without user computer access to indices etc - along with filing system + horse drawn trams a heritage experience