I tried to recover sine data from simple plot.
First you should convert eps file to plain svg (using Inkscape for example). Then you can open the svg file with text editor and copy desired path coordinates. Those values appear to be some kind of differentials of actual path coordinates, so cumsum will reveal actual shape of original plot. Next you should scale derived coordinates with the axis object coordinates (also found in text file of svg).
Probably ruler and pencil would be more appropriate tools for that task :)