Yes, those are the numbers and letters visible in photos
in this photo, the serial number, "HE 575" is in the smaller red letters/numbers over the horizontal stabilizer.
The Squadron ID and plane ID letters/numbers are in large red markings flanking the roundel
F is for FIRE, That burns down the whole town!
U is for URANIUM... BOMBS!
N is for NO SURVIVORS...
- Plankton
LSM