The brass plate is the model identification plate, so that mower is a 14" 1948 model (which I think was produced until replaced by Deejay's model in 1951). My recollection of my 12" seems to include a shorter clutch than that, coloured dark red. (That is, like your wooden handled one, not a long clutch like on your aluminium handled one.) If your wooden-handled ATCO has its plate also, that will give its model date.
Incidentally my catcher was completely made from aluminium, including the rod around the perimeter. The rod had been MIG welded in the top corners - either as reinforcement or (more likely) as repair.
Last edited by grumpy; 10/03/12 04:21 PM. Reason: Clarification