On my old Farmall tractor I have square nuts on the drawbar attachments.
The "bolts: that these are on, are not just bolts, but some special
swivel device similar to an eye bolt. These square nuts are rather large
and need a 1-1/4" open end wrench. The problem is that these nuts are
right next to the transmission and there is no room to swing an open end
wrench. The only way I can get these nuts off, is with a socket. But
even looking at antique tools at auctions, I have never seen a socket
for square nuts?

Normally, if it's just a regular bolt, I'll just use my angle grinder
and grind the nut off, but this is not an option here.

Has anyone ever seen sockets for square nuts, and know a source to buy
them? If they are available, I'm sure the socket would be cheaper than
having to replace those special bolts.

(Once I get them off, they will be replaced with hex nuts).