Can someone please decode this slip yoke for a TH400. On the shaft side of the slip yoke are the numbers

CN3 0779NF

CN3 is on the left side of the yoke and 0779NF on the right side. The C is in question but rest is readable.

If you turn the yoke over there is

B5 GM18
Similarly B5 on left and GM18 on right.

If you look on the shaft end of the circular lip you can see two engraved stamps.

C9 396.

The C is double stamped and I believe that is reads 396 but it is difficult to read.

Thanks in advance.