Mobile app called vFlat to do the scans and OCR. Cleanup in Google Docs. EPUB creation in Calibre. Then for proofing, I read the whole thing on an Onyx Boox, which lets me mark it up with a stylus. Then back to Calibre.
I've spent a good chunk of the year making ebooks from out-of-print dead tree books. Proofing and formatting takes a ton of time. Nobody reads them but me.