[mnehring]

17955 is on display at Edwards so this may be a spare part, a part that was replaced, or a false marking.

http://www.sr-71.org/photogallery/blackbird/17955/

17955 also doesn't have the skunkworks emblem on the tail so I suspect this is probably a very early part that was replaced.

17955 display, tail image

[DogByte6RER]

Thanks for the clarification.

I was just about to transfer the necessary funds into my Paypal account.

: )

[Kirkwood]

Look at photos 19 and above. They have the emblem.