4x4 driveshaft restore question

[71 super]

Trying to get the drive train cleaned and rebuilt so it will be ready when the frame comes home for reassembly. When cleaning the rear driveshaft/prop shaft and installing new u joints, I found the remnants of a stencilled number on the shaft. It looks like 11--55N ; has anyone ever seen this or have an idea what the numbers are or represent? I am going to put them back but would like to know what they are. This truck is covered in factory markings, including the name "John" written upside down on the gas tank . By the way this is 72 4x4 swb built in baltimore, mid year of 72

[Sinisterspeed]

LOL that makes me laugh. (John on the gas tank)

Hows this for factory markings.
In April 07 we built the last Freightliner to come out of the Portland Oregon Plant. This is what it looks like behind all the interior panels as well as inside the frame.

Top LH Corner over the Driver is My Handle, Sinisterspeed 2007 in white pen. Also, My Initial and last name in the last pic somewhere else on the truck.
You should have seen what some people wrote. "Last one built in USA" some other nice things were written under the panels about mexico and where those jobs went. They left it all on there and shipped it with only a couple exceptions, Under the hood and on the engine were a few things that should not be said allowed. I guess the driver that got it wrecked it and the back half of the cab was repainted. I bet they got a kick out of it when they started taking it apart for paint. The writing was EVERYWHERE!

[71 super]

All of the markings on the freightliner would make it more desireable to me, that is too cool. When I got the 4x4 I thought it had been molested more than what is appearing now that it is apart. When I stripped the cab and pulled the gas tank I saw the writing thinking cool, did not realize it said john until tank was sitting against the wall. The frame had several markings on it as well but no other names. The starter is a numbers matching piece and so is the alternator. Anyone have a clue about the shaft???

[arkansas]

I found a stenciled number on the driveshaft of my 71 half ton 2wd also. I think it must be the driveshaft part number. Still debating whether or not to put it back on. Mine is not really going to be a restoration so I may just snap a pic and forget about it for now.