OCR scan images embedded in a PDF

I have a project I'm working on that involves ~1200 pages of PDF documents. Embedded in the PDF's are scanned images of papers, articles, and lectures from the late 1800's.

I'm looking for a Windows software product that will scan the images inside the PDF files using OCR and output to either text or a Word document so I can do searches on the contents without having to pull out the 1200 or so images into separate graphics files for OCR scanning.

This is a personal project so the budget is tiny. Free would be good. I don't have Acrobat to separate out the layers so that's not an option.

Any help will be greatly appreciated.