Hi George and Amanda-
I'd try using the physical address only--unless you are trying to convey that you are a good, "out of town" option for someone headed to the larger community with a post office. We have that issue because we are in a jurisdictional "hole" that is technically outside of city limits, although visitors would perceive it to be part of the city that is a common destination. I think people will find you with the map search.
Also-in more rural places google maps can be messed up--be sure to send them your corrections and that will help with online ambiguities about where you are.
I don't know of any way to list 2 addresses for 1 location, so you probably have to choose between accuracy and communicating which town you are "nearest" to.