The dial on the top of the head of the CT-2 is for calculations - it is not part of the CT-2's electronics. It does tell you how to use the W (winder) and M (manual) settings.

On my CT-2 the two sliders are for film speed and mode selection. The film speed is marked in DIN only. The other slider selects manual, winder (low power, but rapid recycle, or the aperture for auto use - there is a wide range of apertures.

TTL use is only possible with the correct SCA500 adapter.

Is that info any use to you?