Hi,
I search a picture of a U28B no.5539 in SCL/L&N Family Lines System paint ( it must be ´70 or ´80)
Christian from Germany!
Christian,
According to this source:
http://www.thedieselshop.us/SBD.HTML
there was no SBD 5539.
L&N (Louisville & Nashville) bought GE U28B 2500-2504. Here is a 1980 photo of 2503 (which would have been 5539):
http://www.rrpicturearchives.net/showPicture.aspx?id=2938443
I suspect that the locomotive was never changed to 5539. If you want to be correct, it appears you could re-number your loco to either L&N 2503, or SBD 5536-5538, 5540. There are photos online of these, should you wish to do any modification.
Please note that the locos were originally U28B's. But they were modified to become U30B's.
Ed