Last combat of Egon Mayer

[Monaco]

According to Fortier, Norman (2003). An Ace of the Eighth. New York: Ballantine Books. ISBN 978-0-89141-806-1, Egon Mayer fought his last battle against a P-47 pilot of 355th FG, Lt W. Gresham, but this is questionable.
I read this on a Wiki entry and have not Fortier´s book and do not know how he comes to his conclusion (apparently a gun camera footage).
Here is the info I gathered:
Stab of JG.2 took off from Cormeilles with 4 Fw.190s around 1105h and landed at 1230h with the loss of 1 Fw.190 (ref: Caldwell) , that was Egon Mayer´s Fw 190 A-6 (W.Nr. 470 468) (ref: http://www.luftwaffe.cz/mayer.html). The claim by Lieutenant Walter Gresham of the 358th Fighter Squadron of the 355th Fighter Group was made at 1420h and was SE Chaleroi (ref: Olynyk, p.40). Charleroi is located some 170km NNW Montmédy. Gresham´s combat report mentions no bail out of the german pilot after his combat between 15,000-12,000ft (ref: http://www.wwiiaircraftperformance.o...m-2march44.jpg).
I would suggest Mayer was in combat with Maj Robert L. Coffey of the staff flight from 365th Fighter Group claimed 1 Fw.190 W of Luxembourg (70km E of Montmésdy) at 1145h (ref: Olynyk, p.40). The other claims by 9th AF and 8th AF fighters where at other locations and other times. For Coffey it was the first of 6 victories credited to him.
Can anyone add his knowledge to this case? Does anyone have the gun camera footage?
Thanks in advance
Monaco