dsc15766.jpg

Detail of the engine's ID plate (visible on the outrigger just to the right of the valve package). It reads

Apollo Test Capsule

Bell Aerosystems
A Textron Company

Thrust Chamber
Stock No.: <blank> Part No.: 8258-470385-9 Contr No.: NAS 9-1100 Serial No.: H37-385-13

Since this has only a Bell Aerosystems, rather than a Rocketdyne, ID plate, I suspect that this may be an early APS engine. Recall that Bell was encountering difficulties with combustion instability, and Rocketdyne was eventually chosen to produce the injector and integrate the engine.