1. The candohm resistor (2R191) riveted to the rear of a CTC2 chassis is a three-terminal device, except when it is an early production-run chassis, which had only a two-terminal (not-center-tapped) resistor.
2. The vertical-centering potentiometer is a dual-ganged potentiometer in an early chassis only.
3. It is more difficult to find the latter version (single pot) in documentation; Sams describes the little-utilized early production-run (ganged) version only.
4. Finally, check the schematic of the more-common but less-documented single-pot version of vertical centering as shown in this 'production change' supplement by Telaide.