The OLD on this hub is 126mm but as you can see its mounted on a 120mm axle.What's the consensus?Is there enough axle space to mount on a wheel?I'm trying to find an appropriate 137mm long axle for a campagnolo record but it's not easy.O.K. to use like this?

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.

I can see you have almost three threads worth of axle there, I see no issues. It just needs to have enough to hold itself in the drop out, of which yours is sufficient.

In general, a "proper" length rear axle will be 11 mm longer than the OLD, leaving 5.5 mm sticking out beyond each locknut. However, that 5.5 mm isn't sacred and the 2.5 mm you have will be sufficient. In fact Sheldon Brown had an article where he said that actually nearly zero protrusion would be ok since the wheel is really held in place by the pressure of the qr skewer. Here is his take on it:

"Axle Length
Typical quick-release axles are 11 or 12 mm longer than the spacing of the hub locknuts. This gives 5.5-6 mm of axle protrusion on each side. You don't actually need nearly this much, so for respacing hubs to wider spacing, if you're not adding more than, say, 5-6 mm of spacers, you don't need a new axle. As long as you have 2 or 3 mm sticking out on each side, that's plenty.
One of my own bikes is set up with the axle cut off flush with the locknuts, and even this is no problem in use, though it is slightly trickier to align the wheel when installing it. See my page about my fixed-gear mountain bikes."

I thank you all for your responses and can only say whoopee I'm going to use these on my new wheels!!

All of what I was going to say has already been said in the previous posts, so I'll just second all of them. I will tell you it'll work. I have a 126mm axle Campy Record rear hub with the proper 5.5mm spacing at each end. I wanted to use it on a 130mm spaced aluminum frame and didn't want to bend/squeeze the frame in that much. I slipped on an approximately 1.5mm wide washer on each end of the axle as a spacer. There's very little of the axle showing at each end, but it's enough to guide the axle into the dropouts. The quick release pressure holds it in place.