BF109 Relic Purchased eBay August 2016

I have procured what pro-ports to be a piece of a ME (BF) 109E off ebay.
The bent panel is 20mm x 28mm with the painted inscription of:-
ME109 Dunkirk Kent 23rd Sept 1940.

The person was selling on behalf of a friend, who advises her father was in the army during 1940 and must have picked up the piece during his service in the UK then.

Just purchased Luftwaffe Crash Archive Vol 4 10th Sept to 27th Sept 1940.
There's nothing for 23rd Sept, but there is an entry for 17th Sept 1940 for a ME109-E-1 crashing into Church Wood, Dunkirk, near Canterbury, Kent 15.40 hrs. A/C dived into woods after combat & buried itself whilst burning out.
A/C was Wn.3177 (9/JG53) pilot Uffz Manfred Langer + CC 1/181

I believe the Wealden Aviation Group have dug this site & can report their findings. Why my piece has 23rd Sept 1940 I do not know, can only think the panel had the data added at a later date & the person guessed the date as they did not record it accurately at the time. This panel does look like it has been in the ground. Daughter found this piece while sorting through fathers belongings after his death, so looks genuine, as can't believe he would make it up. She had never seen piece before, so he had obviously had the item some time.

Did pilot bale out or die in the crash, as Archive book does not tell me. I can provide photo of part if required.

Any information, gratefully accepted. Thank you.