Another option is to bend the frame to fit the hubs you have available. Of course there are caveats:
1) This is best done with steel.
2) Be sure the dropouts stay parallel and the frame symmetrical. Options range from try-it-and-hope to paying a frame builder to do it perfectly. That could cost more than the hub modifications described.
3) Not a great idea if you need to switch back and forth to 130mm.
With the warnings out of the way, I'll mention that I have a Reynolds 531 road frame which has been widened from 5 speed to 9 speed, and then narrowed back to fixed gear width. No problems, and my LBS did a good job keeping things parallel.