Wespe

The Wespe Self-propelled gun was an artillery vehicle built from the Panzer II chassis. It was primarily manufactured by the FAMO company and designed by Alkett.

IRL

The Wespe was first created after the Fall of France when it was found that the Panzer II chassis was outdated. This lead to ways they could use the Panzer II chassis outside of front-line combat roles. The Alkett firm, having worked with the concept of using outdated chassis to fit new roles in the past with Alfred Becker of Marder fame, looked at the Chassis and said "Hey, we can make this work".

Thus, the Wespe was born as a way to create mobile firepower for the Panzer divisions. In many ways, it was similar to its big brother, the Hummel, only it had a "mere" 10.5 cm howitzer. The design was solid, and despite having all the shortcomings of an open topped combat vehicle, the crews who operated the vehicle held them in high regard for their high manueverability. The design was so popular that Hitler ordered the Panzer II chassis be diverted away from the Marder II program in favor of its production.