Is that a AGM-12B (mass only 600lb) or AGM-12C or D (mass 1800lb)?
In any case, Detail & Scale #04 (old series) and #33 (new series) show pictures of Huns carrying a TER with three Mk 82's (two Slicks, one Snake) on the inners, that's 1600+ pounds. They even list TER's on the inner stations as one of the "standard" loadouts.
AGM-78 weighs from 1350 to 1800 pounds (depending on the model; I can't imagine air-launched STARM's to vary 450lb in weight so presumably the heavyweight is the shipborne RGM-66D version, probably including the liftoff booster), can't find the weight for the required LAU-78/A launch rail but for example the LAU-118/A rail for the AGM-88 weighs 135 pounds.
So based on these figures, if the missile physically fits under the plane (and you can somehow fit the required gear inside the Hun) carrying it is very plausible.
EDIT 2: careless reading, nukes could be only carried on centerline or center wing stations (which by implication are rated at 2100+ pounds), but the above figures are still valid.