Axle replacement?

[spymaster]

Hi all, I'm trying to replace the pitted cones on my old bicycle hub, and as expected, a perfect match is hard to come by. There's so much variation in the cone dimension and threading.
Someone suggested finding a similarly spaced hub with the same axle and cone diameter, and swap the whole axle assembly over, assuming the cones are in good shape. This takes away 2 of the variables: axle threading and cone height.
Will this work? Getting a used replacement axle/cone/spacer assembly might actually be easier than finding the perfect replacement cone in my situation. Is the bearing interface gonna change with my existing hub cups if the cones have a different height?

[DaveM]

This is a good option if you're having trouble finding parts. The new axle/cones don't need to be an exact match, but there are a couple important dimensions to look at.<br />
First, the axle width (or technically the spacing across the locknuts) needs to be the same. Next, the diameter of the bearing surface should be close. Look the the bright ring on the new cones where the bearings sit on the new cones. This should be close (exact not necessary) to the old ones. Finally the diameter of the whole cone ideally would be very close so that they will fit to any dust covers you have on the hub. Otherwise you may have gaps that let dirt in or may have to remove the covers entirely if they rub which is definitely less than ideal.
On a back axle, keep an eye on the spacing between the two sides. The drive side will have much more spacers between the cone and lock nut. You want to try to preserve that width from your old axle because it will affect where your freewheel sits inside the frame.

[spymaster]

Thanks Dave. Well, I got some good news. I was able to find a set of used cones (in good shape) for my front wheel, and a set of new ones for the back. On the back, the cones sit taller by about 0.5mm than the original ones.
This might be enough to throw me into another parts search because I already don't have much axle sticking out on each side (~3mm) originally. I'll see if my LBS has some thinner locknuts to cancel out the extra 0.5mm per side from the new cones + show some more axle to secure against the dropout. My current locknuts are 4.5mm, and there's not additional spacers used.
I hope this is the easy part. Hope I can find some 4.0 or 3.5mm locknuts.