If you have a chance to go back to the archive, you could improve your photos by placing the camera farther from the page and using a more normal focal length on your lens,
Your photo was shot with a 5.9 mm focal length with a 1/2.5" sensor which works out to approximately 35.4 mm.
This is a bit of a wide angle and is producing the barrel distortion that you are seeing.
Also shooting at a slight angle rather that straight on is why there is more distortion at the top compared to the bottom.
Trying something in the 8.4 - 9.2 mm focal length will help reduce the barrel distortion and produce pictures that you won't need to struggle with in Photoshop after the fact.
I understand you might not be able to go back and reshoot these pictures, but a sturdy tripod and some planning (take some test shots at home and see what settings are best) will be helpful for future archive photography.
Good Luck!