Having done several internet searches on this, I've discovered that the modern Plivot airfield was a postwar replacement for an airfield at nearby Athis which ws thoroughly wrecked and not economically viable to rebuild.
There are several German websites about Jg3 - all saying that ii/Jg3 was based at Athis from10th-22nd August 1944. None mention the attack in question but the dates and location are right for the Jedburgh mission I'm interested in. Two of the sites seem to be saying that the 4th staffel no longer existed after Athis - so that might be significant (my German and knowledge of the Luftwaffe are not good enough to be sure). eg
http://www.lexikon-der-wehrmacht.de/...hwader/JG3.htm You will know if this is a reliable source.
But it least it gives me a date range to work on. As I suspected the Jedburgh report was exaggerated - the Udet wasn't "exterminated". At
most a relatively small part of it was destroyed during a raid on Athis airfield. Now I need some documentary evidence for this.
By the way, is the book Paul mentions "Jagdgeschwader 3 "Udet" in World War II: II./JG 3 in Action with the Messerschmitt Bf 109" by Joachim Prien?