looks like a little shoulder to sit on . should work
as far as replacements , not genuine but, I got a 'Wheels of Boulder' replacement axle,
for my <C> record and GS hubs .
they are distributed thru, as usual, QBP. most bike shops have a QBP account.
so really not hard to find.

I put mine in a 130 frame, added a left end spacer, re-tensioned the wheel to recenter it.
lessened the difference in tensioned, side to side.. so improved that too.

FWIW I broke Campag axles, but not the Wheels one,
I think the tempering was a bit too brittle hard on the original ones.