I highly recommend this exhibition at the new Bodleian library in Oxford.

http://genius.bodleian.ox.ac.uk/

There is only one Tolkien piece - his artwork for the dust jacket of The Hobbit - but everything in there is very shiny (often literally as well as figuratively!)

I am now working my way through the catalogue - also very interesting.

http://www.bodleianshop.co.uk/marks-of-genius.html

- wellinghall