This one, which is very much a "work in progress", with the intention to model everything down to the bolt, and yes even the tread on the tires is modeled. For those interested, this model is about 90% sub-division.
The plan is to get back to this one, just as soon as time and motivation allows, and yes it will get a full interior.
As for the available references, yes there is some, just not even close to the 88mm Flak gun. For this one most of them are photos and some really low quality drawings.
This first render shows the finished part of the model, as you can see, the WIP part starts at the windshield and goes back, and is just roughed in. One part which may end up being redone, is the tires, note the spacing on the tred, it's wider than expected.
Close up front lights
This render shows the detail in the front lights, note even the screws are modeled, and the some of the welds on the front grill. And yes most of this is a sub-D model.