dscc4322.jpg

View of two ID plates on the engine's throat.

The left-hand ID plate reads

Rocket Engine Component
Part Name
Thrust Chamber
Contract No.		Part No.
5905		206077-11
Spec No.		Stock No.
Code 4274		[blank]
Serial No.		Model No.
6702		H-1A
Date of Mfg.	Weight	Insp:
1/17/63	[blank]	[inspection stamp]
Rocketdyne
A Division of North American Aviation, Inc.

The right-hand ID plate reads

Rocket Engine Component
Part Name
Thrust Chamber Assembly
Contract No.		Part No.
5905		206076-11
Spec No.		Stock No.
[blank]		Code 7849-1
Serial No.		Model No.
RN012R		H-1A
Date of Mfg.	Weight	Insp:
1-Q-63	[blank]	[inspection stamp]
Rocketdyne
A Division of North American Aviation, Inc.

Normally, a rocket engine has a number of "Rocket Engine Component" ID plates for individual components or subassemblies, plus one overall "Rocket Engine" ID plate bearing the serial number of the entire rocket engine. However, it's not entirely unheard of for the overall rocket engine information to be on a "Rocket Engine Component" ID plate; it usually says "thrust chamber assembly" or "rocket engine assembly."

So, it almost seems that the right-hand ID plate might be the engine's overall ID plate. While Alan Lawrie's Saturn I/IB lists H-1 engines (presumably non-production engines) with serial numbers such as "R048-R" and "R004R", "RN012R" is a slightly different format.

Frequently, the serial number of the thrust chamber is the same as the serial number of the entire thrust chamber assembly (although there are many documented cases where this is not the case with Rocketdyne engines), there are no engines with serial numbers of the form 6xxx (although there are plenty of engines with serials of the form 5xxx and 7xxx).

My best guess is that this is some sort of R&D engine. Plus, while I'm familiar with H-1C and H-1D rocket engines, I'd never heard of an H-1A (although it certainly makes sense that there were H-1A and H-1B engines somewhere along the way).