This is a really, really weird question I realize, but I recently picked up a Snap-on V-21A valve adjusting tool. I bought it on Ebay, and it came with a 5/8" socket attached. I didn't think anything of it as all the ones I've seen have a standard(I think) 1/2" drive, albeit I think only a Snap-On socket will fit properly. Still, that's not a big deal-used Snap-On sockets are cheap. It arrived, and has a strange hex drive socket. Looking around a bit, it seems that the change from hex drive to square drive on this particular tool was made in 1939. That's good and well, except for my uses I need a 1/2" socket. Given that these can be had reliably for $20-30 on Ebay, I'm wondering if I should stick this one on the shelf as as an interesting curio, or if it's worth tracking down a socket for it. Does anyone know if these hex drive sockets had any application other than this, or otherwise if there's any hope of finding one.