Milo Baughman's chair?  

I'm not an expert on Milo Baughman by any means but I do like to do Google image searches and I know that 1st Dibs isn't a great source for accurate identifications. i've heard that 1st Dibs administrators take misattribution seriously but I think they rely on viewers to report it. That's just what I've *heard*, though.
Anyway--I'm guessing your chair is based on this bona fide Milo Baughman chair currently shown on the Thayer Coggin website. I seriously doubt that Baughman would have designed two chairs that looked that much alike, whose differences are essentially just aesthetic.
http://www.thayercoggin.com/coopermb.html#sthash.Wx4oBvUu.dpbs
Dealers do this a lot...they have something they aren't sure about, they do a quick search and find something that looks like a good match but they don't check it out too thoroughly, they write it up and toss it on the internet. Maybe they're sure it's accurate or maybe they have doubts but are hoping no one will ask. Maybe they got the ID from someone they think knows more than they do. Who knows. You are right not to assume that the ID is correct.
I don't know who made your chairs. My guess---and that's all it is---is that they were designed by committee for a furniture manufacturer who wanted the look of that Baughman chair but with enough differences that it wouldn't be design theft.

The pair of chairs on Dibs are most certainly not Baughman. They were made by the Home Chair Company out of North or South Carolina. I've made fully marked examples in the past