Hi,
as said, the model built by D. is from Verlinden and has several mistakes. If you want to add more detail like open hatches, etc. you can go with the mixed media kit offered by FONDERIE MINIATURE, though you must expect a typical FM kit here. You can have a look at the parts on their website:
http://www.fonderie-miniature.fr/draisart.htm#Grappe
Plastic car with resin turret. Still you have the option to throw in a turret from the Tamiya kit plus an Armorscale, Armo etc. barrel.
HTH
Frank