WOW! Thanks for all the replies. Going with the those that believe I might be over thinking this. Only three states will not give you a credit for paying sales tax in another state and WV is one of them.
I'll have a bill of sale, title (signed), proof of insurance and my license and head for home. I'll pay my fair and required tax in WV.
Think of it this way; if the seller was visiting here in WV, had their title with them and wanted to sell me the RV, should I call FL and tell them I want to pay them 6% tax? I think not. Go to my DMV and pay the tax and sleep just fine.
Thanks again for your replies.