Car tire shops won't know what to do as a general rule.
Semi truck and farm tractor tire shops will, or as previously mentioned any tire shop that's been around for dozens and dozens of years.

Likely you have lock ring wheels and not "split rims" check the pictures and definitions in this tech tip http://www.stovebolt.com/techtips/wheels/
Pretty much the only ones that no one will, or should, work on are the Firestone RH-5 design. Nor should you mess with any type of multi piece wheel in bad shape (rusted).

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-