Here is the blueprint for the Pz II Ausf c (lower case). This was the first Pz II to have the five road wheels. They built 74 of these. The Ausf A, B and C which followed took this as the base, and added improvements. Some were internal, and some were small visible changes. I am including it here as a baseline.
Here is the blueprint for the Ausf A. Biggest changes were the peaked driver's visor, and the one-piecve radio operator's hatch. Keen eyed observers will note that the Ausf A had just one fire extinguisher on the left-rear fender. The one that was on the right-front fender has been done away with (you will see it on the Ausf c diagram).
Here is the blueprint for the Ausf B. This one has bullet deflectors around the turret ring, and by the two forward facing visors. Two more subtle changes ... there is now a reinforcing bar across the rear hull, and if you know where to look, there is a scalloped piece of metal welded to the rear engine compartment It was scalloped to make the weld longer. This was used to reinforce the engine compartment because earlier models started cracking right here.
Here is the blueprint for the Ausf C. The visors have changed slightly,
And here is a blueprint showing an Ausf B that has been back-fitted with several authorized upgrades. This one has ALSO been given the "Tropen" upgrade, because it is headed to North Africa. This includes larger louvers on the radio operators hatch, and new louvers on the left-rear engine deck (over the radiator).
There is one more scan I meant to take and upload, showing the differences in the driver's vision port, and the vision ports around the vehicle (but I have not had the time to get to that one yet).
Enjoy