Replace the axle...

1) Be careful to replace the existing spacers, if any, in the proper order on the side of the hub they came off of.
2) Measure the hub and the dropout spacing. You might find the hub is actually 120.5 and the dropout 125.5 or some other combination of slightly weird measurements.
3) Split the difference between two NEW spacers, one each side of the hub, that take up as much of the gap as possible, i.e., if your difference ends up being 5mm, use 2 x 2mm spacers. If it really is 6mm, use 3mm worth of spacers each side. You might have to use 2mm and 1mm, depends on what you can get.

Figure that all out before you order your axle from loosescrews, they have the spacers too.

Easy as cake...dish not affected so long as existing spacers go back on the side they came off of and new spacers are added equally each side of the hub.