After visiting the National Gallery today I popped into Quinto on Charing Cross Road and was delighted to find a cheap copy of In the National Gallery: A first introduction to the works of the early Italian Schools as there represented. By Mrs. C.R.Peers with many illustrations, published by the Medici Society in 1922. It's a lavish production, leather bound with gilt edges and some early colour pictures. The wonderfully archaic text hasn't really endured, but its value to me is in the old photographs taken before the disastrous campaign of 'restoration' undertaken by Helmut Ruhemann. The colour picture of Uccello's Battle of San Romano (recent picture above) is a bit grainy and I can't get a decent scan, but it's quite different from its current appearance. It shows areas of sky painted over the original landscape (now removed). In 1922 it was already tragically over-cleaned, with broad flat areas of grey and white in the horse, but even in this grainy picture I discern more subtlety than is present today.
Even when they're in the bargain box, books like this rarely seem to sell. The Internet offers fantastic opportunities for art historical research, but it's a shame to neglect old books.