dsc46180.jpg

The main rocket engine ID plate (identifying this as J-2120) and several modification identification plates; the "MD Ident" plates appears to be the same as the F-1's RD171-1022-0001 MD Ident plate (and, indeed, the J-2 Rocket Engine Technical Manual: Illustrated Parts Breakdown lists "RD171-1022-0001" as a part number on the J-2).

Picture 2 of 2.

The main ID plate reads

Rocket Engine
Part Name
Rocket Engine Assembly
Contract No.	Part No.
NAS8-19	103826
Spec No.	Stock No.
R-21586S	[blank]
Serial No.	Model No.
J-2120	J-2
Accepted Weight Insp. [blank] 3444 [stamp]
Rocketdyne
A Division of North American Aviation