Hi John!
I have a polish magazine called "messerschmitt Bf 109" published by AJ-PRESS in 1999 and written by Robert Michulec.
The mail address is
ajpress@kki.net.pl
In the magazine there is a colour profile showing Kühleins mount
Also in the book "Luftwaffe photo-report 1919 - 1945" by Karl Ries and published by Motorbuch Verlag You will find a photo of his airplane and a photo of him sitting next to Ln. Günther Stedtfeld, Stkpt. of 7./JG 51
I do not know if this helps You a little. Unfortunately I do not have a scanner at home, but if You can´t find any of these, then contact me again and I will see what I can do!
Good luck on Your very interesting project, would love to see some pictures on Your progress
Christian