Then Kagi can find me high-rez scans of these sources, at the @internetarchive and/or the Library of Congress. I snag those PDFs and import them into the GIMP (which I use for editing) and pull, clean and crop a new high-rez version of those images for my own use. This year, I got much better at saving and organizing all that work on my laptop, but next year I'm hoping to get into a rhythm of uploading my high-rezzes to Wikimedia Commons so everyone can use 'em.
7/