The Americans found them at the manufacturing plant Steyr in Münichholz. Other sources talk about Augsburg. Two of them were at Breslau, nearly finished, the Russians got them.
I found on the internet, that one unit was ready to be taken over by the German Wehrmacht.
Who knows, but anyway, none of them saw action.
Tecnical data are not really reliable, what I found are these data:
total length: 14390 mm
width: 3000 mm
height: 3640 mm
As a basement for my 3D drawing I used the really good book "Panzerzug Teil 2 " from Waldemar Trojca. There you find a drawing from where I took my dimensions.
So here is the first preview after some hours.
And here with the first details, even I have to add much more, but you can already see the progress.