I am trying to help a friend find a 13' Scamp, and there is one for sale in TN.  A 2000 model, and the ad says they added the roof air unit in 2014.  It seems I read that the Scamp needs extra bracing from the factory for roof air, but I couldn't find an article in the archives.  It might be they REPLACED the roof air.  I thought I would check here first though--is it possible to have a roof unit added safely to a Scamp not set up for it originally?  Ha ha ha, probably a moot point as we are in MI and probably can't zip down to TN fast enough to snatch it anyway!