How do you tell leather from leather like seat covers?

Cut it. Leather is obvious.

Of course, that kind of defeats the whole thing, right?

I believe the leather-like covers are still a type of vinyl. Take some saddle soap, clean the, and see if they change color slightly. Leather will from it soaking in the soap and water. Then use a good leather preservative (good shoe store has it, as will a western saddle shop) and it will soak in.

The leather-like, it should all stay on the outside.