John, This is how someone like me tells the difference.
The photos in this thread show a Cab 11. It has a small flat bonnet (hood- engine access panel) which is a single plane flat panel.
The Cab 12 has a slightly larger hood that incorporates the angled panels that angle down to the head lights when veiwed from the front (so 3 planes- bigger hole- still rediculous access) The Cab 13 has the reverse angled windscreen glass. The Cab 13 has room for people with 2 legs, with feet on them.
