Have you tried a camper store? There is one out on 70 towards Clayton, have no idea if they have prop. I used to get it in Garner but that camper place closed up shop years ago.
Exxon at Crossroads, Uhaul on Chatham Street, Burk Bros. Hardware, There's many!!! A phone book wuld be a better source unless you wanted to pinpoint an exact location?