Someone at the British Library has had an excellent idea. They’ve uploaded a spreadsheet listing all the manuscripts they have online, with the URL. It’s here. They have 856 mss online at the moment; a small proportion of their holdings, but still very useful.
The spreadsheet lists shelfmark, contents, url and the project that did the upload. The last won’t be much use, but browsing down the list of contents is exciting!
It will be very useful to me on my current project too.