Had been mindful (emnhmoneuon)-- would have had (eicon an). Condition of second class (note an in conclusion) with the imperfect (not aorist) in both condition and conclusion. So it means: "If they had continued mindful, they would have kept on having (linear action in both cases in past time). Opportunity to return (kairon anakampsai). Old verb anakamptw to bend back, to turn back ( Matthew 2:12 ), here first aorist active infinitive. Continual hankering would have found a way. Cf. the Israelites in the wilderness yearning after Egypt.