Contact Rickman Aircraft in Columbus, just west of Laurel. I'm not sure he is still mechanicing (is that a word?) as he is mostly flying pipelines but could steer you in the right direction.
Aerotronics, the avionics company based in Billings uses an A&P on the field when they need A&P type stuff done. I have no idea if the person is any good, but I would assume they have at least seen an RV before. You could call Aerotronics and ask if they have a recommendation. Sorry I don't have any first hand knowledge or info about the person.