Headquarter 3 and headquarter 5 are essentially the same building. I think headquarter 3 is wrong: It is now (in player/playerbuildings.dat):
Obj=building
type=hq
Name=3headquarter
copyright=raven
NoInfo=1
hq_level=2
passengers=150
intro_year=1935
BackImage[0][0][0][1][0][0]=HQ.0.4
BackImage[0][0][0][0][0][0]=HQ.1.4
and most likely it should be:
Obj=building
type=hq
Name=3headquarter
copyright=raven
NoInfo=1
hq_level=2
passengers=150
intro_year=1935
BackImage[0][0][0][1][0][0]=HQ.0.6
BackImage[0][0][0][0][0][0]=HQ.1.6
Thanks, indeed.
I was wondering about the same thing yesterday, but didn't have the time to check whether I had interpreted the data wrong or whether I could find the cause.