Those aren't ball-lock kegs and without knowing the exact threading on the posts, you are unlikely to be able to convert them.
I'd say you have a primary regulator and three secondaries that are usable, but the rest probably isn't.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk