Any good machine shop should be able to fabricate a set of spacers, but be aware you'll also have to install longer lug studs to accommodate them. They will be e$$pensive! Do you still intend to run dual wheels? If so, remember to make the new hub-centric area wide enough to handle centering both wheels. I'd strongly recommend steel, not aluminum for the spacers.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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