Some background info for further discussion:
Panzer III- The running gear design changed considerably during the developmental period.
- Ausf A to Ausf D had totally different lower hull design.
- Ausf E to Ausf G are using the same lower hull design.
- From Ausf H onward, there are some design changes, but had remained the same until the end of the variants (Ausf N).
Panzer IV- The running gear design had been quite stable throughout development.
- Ausf A upper hull design is unique.
- Ausf B to Ausf E had a similar upper hull design and layout.
- Ausf F to Ausf H had minor layout changes with up-armoured modifications.
- Ausf F to Ausf H also had several up-gun changes as well.
- Ausf J had exhaust changes.
Comments welcome!