[Ivo de Jong]

This is getting very interesting....
I looked at the photo in Fry's "Eagles of Duxford", as Michal indicated. It is on page 47 in my copy, by the way. The photo caption tells us that it is P-47 MX-K 42-8505. On the photo in the book the serial is not legible, but the fuselage code is (thus note that it has a bar under the K). It is an olive-drab machine.
Close examination of the nose art shows that there is a small "II" behind Jack, that thus wasn't noticed by Gary Fry. Coincidently, I have a close up of this interesting piece of nose art, which I would like to have attached for your interest, if I knew how to do it.. I'll send it to you off board. Apparently the original "Smilin Jack" was lost or scrapped, and its successor was flown by Bernhard for some time.
According to Fry, Bernhard flew with the Group from Feb 23, 1943 to June 16, 1944 when he transferred out. He had no credited air-to-air victories, so was one of those unsung heroes who did not get a 'kill', but did all to protect their 'big friends'.
Hope this helps.
Ivo de Jong