If you still wish to work on the images, and they all have the same margins, and if you use a variety of MS Windows, you could try
Irfanview's batch options, which I believe include cropping.
I used to install Irfanview on pretty much any MS Windows machine I had, and work's, and on those of friends and family (after explaining, and being given permission). It was my default "image viewer" of choice.
Cheers,
Marc