Ensign selfix 12/20 and 16/30 are designed to take either 620 or 120, as were the selfix 820, I have bought both a 12/20 and a 16/20 complete with 620 spools in the take up chamber, and Mike, the Ensign selfix models have spring loaded posts with a small post for 620 and thicker post for 120, perhaps they were the cameras you were thinking of ?
Richard