Burnside Carbine identified?

[Bugattimiller]

I have been looking at a mismatched Burnside carbine and there are some markings on the butt which seem quite interesting. As seen in the photo there is N C T CO D 9 TE with what looks like a later added N or M. I know there were both union and confederate 9th Tennessee cavalry regiments but I don't believe the federal unit had a company D, or was it an infantry pick up? Just wondered if anyone can shed more light, always difficult when it is only initials.

 

[BuckPvt]

The "9 TE" bothers me. TE isn't an abbreviation that I've ever seen used, and any carving after that isn't consistent with what's before it. I wonder if that part of the stock was worn or damaged and it was re-carved in.

The "9" bothers me too. In the 19th century a 9 would have been written starting at the top, going around the loop, and then the vertical. But this one starts on the bottom of the loop and goes around to the top and back down. A "2" on the otherhand would have stated like that, so I partially wonder if it's a 2 that lost the bottom of the carving to wear or damage. Now admittedly, caving wood and writing aren't the same skill.

 

[Jeff in Ohio]

There is an N after the TE in that carving - it is lightly scratched in the wood and has not yet been deepened with a blade. You can see some places in the other letters where part of an individual letter shows the underlying scratch but was not carved. So, this does sat TEN.
I've seen carvings in person that I believe to be authentically old where there is that same pattern - especially at the end of an inscription where the carver must have run out of energy!
On this one looks like the guy stopped carving after making a small chip on the cross line of the H. Maybe he cut himself at that point!
And I haven't looked it up, but it's hard to imagine any regiment not having a company D.