Seems like adding a wheel center as a washer isn't that big of a deal to me... presuming we're talking about a hub centric wheel. If that's too ugly, put some washers behind the lug nuts. The nuts are only there to hold the wheel flat to the hub (and obviously on) they are not critical in managing the wheel loading on the hub.
How oversized are we talking here? There is a small amount of oversize (tolerance) to the holes already otherwise you'd never get them on, what's a little more?
