I think 7/16 hex drive is standard, the sockets would need a bit of clearance to make them easy to use. 1/64" clearance sounds about right, maybe they are a little worn too.
I managed to offload 2 boxed sets recently
I gave a worthy cause some top quality offcuts (my view - maybe not his ) to use on his lathe and hid a couple of bonus items under the bigger scrap stuff
I'd advertised them and a few other older tools cheap locally (gumtree, facebook, etc) but had no interest.