Get the original files and work from them.
There's a reason why math is ``penalty copy''.
Hevea or latex2html will make the small bitmap images which you are wanting (given a TeX source).
Failing that, run the images through a system which will convert them to TeX code such as Infty's equation recognition system or the Freehand Formula Entry System:
http://research.cs.queensu.ca/drl//ffes/
William