Thank you Bird. Sounds like you have a strong clever dog their to come back after an hour. lol
Few years ago, was lamping with a man that had the same x, dam being a slovakian GSD and sire a marathon greyhound. This dog was black and took everything full on as you say, however, he was a deadly guard dog with it and would sense anything or anyone about and would growl, letting his owner know something was up. The dog got him out of some sticky situations, amazing to watch.
Was their many in the litter Bird? How did the rest turn out?