Hi Gary
According to my references the Luftwaffe flew intruder missions from quite early on, and the failure to continue them into the last years of the war is often cited as a blunder. The Spanner-Anlage system proved to be of very limited value, though, as it was very unreliable and could not differentiate between friend and foe.
More importantly, I'm pleased to see the first of the Do-17s come through. ICM have a great series building.

All the best
Rowan