I've read through all three threads and agree fault on both sides, but I'm glad it's ended at least somewhat amicably. I sell machines for a living and I'm lucky I haven't had to deal with anything this extensive. Knock on wood that I never will.
That being said, OP, if your intention is to eventually open a business full of these things, you just learned the most valuable lesson you can. I agree with a previous sentiment of going to get purchases yourself, doing a thorough inspection, and loading them and taking them home. I rarely buy anything even after getting pictures and videos unless I've also put my hands on it. I know it was some distance, but that's the nature of what we do. Sometimes the thing you want is two states over. These goods are very limited in number. I drive to wherever it is, I take a thorough look inside and out, I pay cash, and take it and go. If it's not as described, I point it out and negotiate. If we can't come to terms, I walk away and lose out on that gas and time. It happens.
If you do amass a collection and would like advice on opening a business (unless I'm misremembering and that's not your intention) feel free to reach out here. Several people have done the same. I've also helped open (and maintain) several businesses in my area so the experience is here for you to pull from.