Fews RV shps actually do tire service - most would send it out anyway. I'd go to a good alignment shop (not necessarily a tire shop). Sinc eyou have a large vehicle, I'd try a shop that handles large trucks.
It's not real close to you, but there is an excellent alignment shop in Westfield, Mass (West Springfield area). It is Hyder's Safety Service and I think their phone is (413) 568-4414. They are experienced with motorhomes and can handle the solid front axle on your F53, which passenger car facilities cannot do. I've had an alignment there and so have friends of mine and we recommend them highly.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL