Yes 130mm should be no problem in a 126mm. Sheldon's word is kind of the final "truth". However if you are on tour it is a hell of a lot easier if you don't have a wheel wedged in there when you need to change a flat. I agree with Miyata 610, your LBS should not have sold you a 135mm spaced hub in the first place. I think you are entiled to demand they replace the wheel with a 130 at their expense (since the wheel is not used).
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1 Super Record bike, 1 Nuovo Record bike, 1 Pista, 1 Road, 1 Cyclocross/Allrounder, 1 MTB, 1 Touring, 1 Fixed gear