The county library service just rang to say they have in the copy of Harker that they obtained for me via the inter=library loan service (cost 50 pence). So no more squinting at Harker on-screen for a while.

They have obtained a number of expensive things for me, including works by Sharp/Karpeles. Worth a try rather than paying for expensive books, though they cannot get everything as some Universities won't lend books to public libraries.