The frame could be cold set the "wrong"
way but why not just add a 2 mm spacer under each locknut of the 130 mm hub? The resulting reduction in axle protrusion will still leave plenty (3.5 mm on each end) to locate the wheel properly and you won't have to modify the frame.
As to finding 135 mm hubs on road wheels, I think there are plenty out there or you could have a 700C rim laced to an MTB hub. Come to think of it, isn't that what 29" wheel MTB's use as standard equipment?