I should have thought of this before. Inkscape makes it easy to add links to them.
The header and footer images are now SVG and the footer image is clickable with target="_blank" in it. Getting them to center was the hardest part but that was no chore either.
The file sizes are now 1/4 to 1/3 of the original image.
Works great in Cyberfox v20.0, Chrome v27, and IE10 for Windows 7.