I can understand how you came to that conclusion. I didn't really give much detail.
I focused critically on an object well into the infinity range of the lens. I removed the bellows, put one end of a stainless steel ruler ( that reads in tenths of an inch) directly against against the ground glass and measured to the plane of the shutter blades, figuring that was pretty much the center of the lens. Not absolutely accurate but it definately fell between 5.1" and 5.3". 5.9" fell out in front of the lens. I'm pretty confident of the measurement but man, that's quite a bit off the stated focal length.