The original Callaway A1 turbo kit, as sold by New Dimensions after they acquired all rights to the Callaway V-dub stuff.
A drawing showing where the Callaway oil return is drilled through the back of the block.
A pic of the actual hole in the block.
An advertisement for a Callaway turbo kit, maybe from a ND catalog.
The March, 1983 article from Car&Driver about the Callaway Turbo Scirocco.
A picture of the bottom of a Callaway turbo motor in what I believe to be an A1 chassis (no subframe, A1-like relay shaft). The wastegate is in the lower right; note the beefy brace with the axle notch going over (under) the WG.