WWIIOL have that German gun sight working.
Citabria, you mentioned you didn't know how it worked. It's basically a dial - it would rotate anti-clockwise to set the distance of the target. In doing so the triangle in the centre would move downwards. Since the scale is 0-40, I would assume this is 0-4000 metres. The chevrons next to the triangle are there to assist hitting a moving target and/or to help when you're on uneven camber.
The right hand sight is the 88mm main gun; the left hand sight is the co-axial MG with it's own range markers.
Doh, just read the bit you quoted from the website!
Here's a screenie from WWIIOL firing a HEAT round from a Pnzr IV.D - it's perched on top of a hill, at a camber, hence having to firing off centre.
