67 Header panel Date code stamp

[MyRed67]

  Can someone tell me approximately where to look for the date code stamp on a 67 Header panel?  I'm pretty sure it is the original, but it is really Heavy surface rust on the underside.  I think I read somewhere that the underside of the Header Panel was Bare metal from the factory, which would explain why mine is so rusty.  Any help is much appreciated!  Thanks!

[JohnZ]

It's on the return flange at the front of the panel, about 6" toward the passenger side from center, between the two pierced holes; photos below. The panel wasn't bare metal from the factory - it was flow-coat/dip-primed on all surfaces and baked before it was color-coated.

[MyRed67]

 Thanks John, I found a partial 4.  All other date codes that I have found are 42 or 43. I'm assuming the car was built around 45 (1 st. week of Nov.)