On another forum a pic that was posted a while back with German tankers playing with a model tank. One of the memebers thought this might work.

I found a 120MM Verlinden, Panzerfurher. He was holding a map in the left hand and a pipe in the right. I modified the hands to be more open palmed, made new buttons for the tunic and pants and added shoe laces to the shoes. And of course... a 144th StugIII.

You already know what the base will be

That's creative thinking Marc.

From what I read 120mm figures are 1/16.

If that's the case this figures represents a man holding a 1/9 Stug Model right?

Thanks Alexander. A Stug in 1/9 scale would be about 2.5 feet so that looks about right.