Hi, Keith. Looks like not many people are looking at this sub-board lately.
To try to answer your question: I guess you’re wanting to convert the images to a clean black & white, and smooth out those lines without losing too much detail. Any free app should be able to do those things. GIMP is probably the best free one around, albeit with a steep learning curve if you want to get right into restoring; but it shouldn’t take too long to learn how to use a few of its basic tools.
To take it further—if you’re wanting to really sharpen the images as well…
Traditional apps can’t effectively both smooth and sharpen the one image without a lot of painstaking manual work. Smoother means less sharp, sharper means less smooth.
Enter AI. Whereas traditional tools manipulate existing pixels, AI tools make up new pixels, so that, potentially, they can both smooth and sharpen an image at the same time. However, to date, it seems most companies producing AI apps design their tools to create images that look great but at the cost of only resembling (more or less) the original rather than restoring it. Only the more expensive ones seem to aim to actually restore images using AI.
So, have a look at some of the free and/or cheap apps online, download one or two and give them a run, bearing in mind that further improvements will probably only come at the cost of more work or more money.
And of course, post any you’re not happy with on here to see what restorers can do with them.

Peter