Some other pictures which might help!!
Love this picture.
One thing I have noticed but which may not matter is the hood (bonnet) chrome work changes. Sometimes it is the flat shape over the bonnet nose and others its the rib type as in the picture above. The rib type seems to be the earlier I think according to brochures. Windscreen wipers also moved from below the windscreen to above it, presumably when the opening front windscreen was fitted. Front mudguards also are different and seem particular to country of manufacture. US and Canada seem to have what I call the full curve, Germany is more like the dodge, no side curve with a short running board, Australia has a cut away curved front and less side curve, India well, who knows!!! and South Africa I dinna ken!
Nigel