SERVICE MANUAL

As others have said, they are really handy. Yeah they are available online but there are just some maintenance jobs that are so much easier to do with a paper copy than scrolling through on a screen.

Those look to be in great shape too. I bought my pair of 75 manuals at a swap meet in the early ‘90s and they are still holding up well even though they are more worn than your pair.
I have been really scavenging all the 75 dart paperwork I can find here lately lol. I bought a 1975 dodge dart dealer brochure on ebay for like 6 bucks and I found a original 1975 dodge Plymouth Chrysler lineup brochure im bidding on now. I bought a extra owner's manual I thought it would be a good idea to have one to put away as a keepsake and I want to keep one in the glovebox just for appearance