Both an Army Good Conduct Medal (2 awards - 6 years) and an Air Force Longevity ribbon (4 years); I don't think there is anything else with it and disagree that it's "obviously one of at least a pair of ribbon bars." At best it stands alone as a guy who did a few years of service, but did nothing special during his service.
The Air Force Good Conduct Medal wasn't awarded until 1963; from 1947-63 USAF still received the Army medal. After 1963, they could wear both - so this would make it prior to 1963 I would say. Longevity ribbon insituted 1957, but retroactive to 1947. So, I would say this guy served more like late '50s. One might think WWII to add a row, but any campaign medals would have to go between the GCM and the Army Occupation Medal and there are none. Korea would have campaign medals between the AOM and the Longevity ribbon and there are none. So, this row is complete as it stands.
Of course, if we want to assume it's "real" (I suspect it may even be made up) and that the owner had no campaign service - other than Germany Occupation duty - and considering the relative high precedence of the Good Conduct Medal (only achievement, commendation, meritorious, and valor awards above); best case = it's a stand alone row/bar. The only other chance might be for a single ribbon top row of either an Army or Air Force Commendation medal (1941 and 1958 respective - prior to '58, USAF received the Army medal) for extraordinary achievement or significant meritorious service during one of his assignments.
When and where should I expect Ms. Fox to pick me up?