Chris, Peter,
I agree with you, Chris, it´s an Bf109G-6/trop of 6./JG51. This plane was built in the Messerschmitt Regensburg Plant, please see for reference Prien, Jagdfliegerverbände Part 11/I, page 330 (photo-No. 247) for example and another three photos of a Bf109G-6 trop yellow 13 on page 341 in the same book (photo-Nos. 257 to 259). Photo 259 is an colour picture of yellow 13!
Best regards.
Bernd