Thanks guys!
I have just uploaded the first production version candidate and am having a test run printed. This is the "drop in" version that should replace the kit parts without modification. I also have a version underway that will include the detail on the bottom of the tank, though it doesn't show and will require modifying the kit fuselage to make it fit.
As you can see the "drop-in" version has a hollow back; I've left it up to the modeler to fill this or not as he or she sees fit. Having the tank shelled makes quite bit of difference in cost.
The accessory sprue has 8 fuel caps along with the fuel guage float sender top.
Here are some renderings of the finished stuff (added a few details, including the ZAK stamp for Bertl
):
