Dear David,
We can find these on net:
http://www.asisbiz.com/il2/Bf-109F/B...e-1941-01.html
http://www.asisbiz.com/il2/Bf-109F/B...e-1941-01.html
http://www.asisbiz.com/il2/Bf-109F/B...e-1941-02.html
http://www.asisbiz.com/il2/Bf-109F/B...e-1941-03.html
So normaly (roughly) we have two white 1. Main visible difference being the III.Gr. Balken position with Black cross... after we can discuss about mottle and Black "flamme" protection at wing root (same on Weisses <II)
6720 is the one with closest positioned gruppe balken in relation with black cross; and with the scoreboard.
On original photoalbum we got the two last pictures above (post #1), another one with scoreboard and a navyman sat on tail with a dog and a last one picturing the dismounted plane being trailed; scoreboard visible.
That last one has been offered in auction quite recently, alone, in highest definition too. (Of course I got it, I don't know where it is right now ... Inside some kind of "shoe box".)
If I remember well (if I understood too) Mr. Erik Mombeeck got some pics concerning that accident (Or he thinks he got ... Have to check his mail

) through Egon's family.
Last: Concerning Quend-Plage and/or St Quentin.
Definitively some accidents in JG 2 lost list have been situated in St. Quentin by German reporter/secretary but it's wrong ... and impossible so far. True place is Quend-plage as rightly noted in the photo album.
And album owner wrote: "RK Meyer" ... what else?
Regards, Franck. Tschüss.