[Aktungbby]

Originally Posted by Von Due

Here's the thing:

There is one particular aircraft that flew during WW2 before being shot down. It was a Heinkel 111 with the ID code 5J + CN. I am attempting to place that aircraft in the squadron it flew, if possible down to its number within the squadron, so to know that plane's individual place in the squadron.

U mean this one?

Early in the morning of the 26th April 1940, four members of KG 4 took off in their Heinkel He111 P-2 5J+CN from Fernebu, Oslo in Norway. One of three Heinkels tasked with attacking the town of Andalsnes, the bomber was damaged by the guns of HMS Manchester. Unable to keep formation with the other Heinkels the crew were then taken by surprise by two Blackburn Skuas of No. 801 Squadron FAA from HMS Ark Royal.
The pilot of Skua A7-A unleashed a hail of machine gun fire on the bomber - killing flight engineer Willi Stock. With one engine failing and the other on fire, pilot Richard Gumbrecht had no choice but to force-land somewhere among the snow covered mountains below. With Stock dead, the remaining three crew members escaped the wreckage and made their way down the mountain. The largely intact Heinkel sat on the mountain for over 30 years, before being recovered and restored by the Norwegian Armed Forces Aircraft Collection.

I have it in my extensive Corgi collection
Fornebu Airfield, Oslo under Luftwaffe control. note photo date vs mission date-the plane is probably in the shot! http://www.nuav.net/ooblw.html Your BBY is currently on display at the Norwegian Armed Forces Aircraft Collection
note the stylish 'c' also in the unit emblem.