Thanks for the link Leendert, what a fascinating record.
For some reason your link took me to page 83, but I think I found the relevant info on page 445:
https://catalog.archives.gov/id/2327...objectPage=445
613 Sqn lost three Mustangs on the morning of July 18th, but later than 07.15:
Following on in the ORB entry in my post #5:
...went to NORTH COATES where the photos were developed.
In the meantime the Y Service had reported that a large merchant ship had joined the convoy and the Squadron was ordered to check. F/Lt. H. GORE [AG656], F/Os J. S. TRESEDER [AG568], C. H. PIGG [AG567] and H. G. TAVERNER (R.C.A.F.) [AM175] took off at 10.10 hrs, made landfall at DEN HELDER and flew South sighting the convoy South of EGMOND. The pilots climbed to 500’ to take photos and were just turning for home when they were attacked by about 8 enemy aircraft including Me.109Gs and FW.190s. The dog fight lasted 8 minutes, and F/O C. H. PIGG was the only one to return. He made a head-on attack on a FW.190 but did not observe the results and suffered damage to his own propeller. He then made two attacks on a Me.109 and saw it dive into the sea. He also saw one Mustang with Glycol streaming from it making for the Dutch coast and another aircraft which was possibly a Mustang dive into the sea. Unable to make R/T contact with the others he turned for home and landed at COLTISHALL.
The convoy was attacked in the evening by Beaufighters with fighter escort and two ships were damaged.
According to the
ASN:
Three P-51 Mustang MkI (AM 175 AG 568 and AG 656) of 613 Squadron, shot down on 18 July 1943 by either flak or fighters during a low level sortie over Scheveningnen, Netherlands, probably in order to carry out attacks on ships near Den Helder. All three pilots were posted as missing/killed in action as all three aircraft were reported to have crashed into the North Sea.
Regards
Simon