Small world - I'm currently cleaning up scans of the EB 9th edition to put it online as a mediawiki site; I'm including all the illustrations and plates so I'm only a third of the way through.
I've been testing different OCR tools and so far I've been the most impressed with paddleOCR - it correctly split the text columns, labled the illustrations, and noted the maragin text.
Still, it's not perfect, so I'm having to hand-edit some tables. I plan to put the source pages online as well so you can switch between the scanned page and the electronic text.