The Victoria and Albert Museum in London has an interesting collection of instruments - lots of theorbos (lutes with extra unfretted bass strings) - though that link I gave is pretty horribly gimmicky, and very hard to use, all part of the modernising process of turning museums into wannabee theme parks.

I'm glad to hear the Pitt Rivers is still a proper museum. Headphone guides, now that is the type of modernisation that makes sense. It's the patronising sort of changes that get up my nose that pretends to flatter people while really sneering at them.