Hello guys
If the information by Boiten is correct it would appear that Oberleutnant Kurt Welter (63 victories, RK-EL) was indeed the top scoring anti-Mosquito ace. He does appear to have definitely shot down five RAF Mosquito twin-engined aircraft and possibly/probably seven others. Here is what I have on this fellow. Any comments or corrections will be welcome.
http://rapidshare.com/files/339866077/Welter.rar.html
Horrido!
Leo