No markings at all. It looks like there might have been screws in the holes toward the middle of the legs. We are thinking about buying a wooden rod and screwing it in there for support.
The frame came from a friend of my friend's whose mother quilted all her life and this was her frame and he had no idea where she bought it.
I got it for a steal and I'm thrilled. It's just wobbly.
I was impressed it didn't fall down with the cat on it though :)