Metz flashes of different models may look similar, even the connectors look similar, but they can be very different. Data on older models (e.g. 45CT1) are sketchy, so research before buying anything.
I'm not sure that the 45CT1 can be used with an SCA372. If it can, you'll need a dedicate cord to connect the 45CT1 to the SCA372.
From what I know, the 45CT1 does not work with dedicated module. The connector of the SCA300A dedicate cord fits only the 45CT3/4 and 45CL3/4.
Your 45CT1 should come with a simple sync cord with a pc terminal as in this photo.
The model number of the coiled sync cord is 5520, straight sync cord is 5522.
If your camera has a pc terminal, just plug it in and shoot. If your camera doesn't, you'll need to find an adapter from hotshoe to pc terminal (assuming the flash's trigger voltage is safe for your camera).
But best for the 45CT1 is a Mecamat remote sensor model 45-20. The 45-20 is attached to the camera's hotshoe. Besides providing the sync between the camera and the flash, it does several things:
1. It has a light sensor which takes over the light sensor on the flash body. No matter where the flash is facing, the sensor always faces in front of the camera.
2. The camera has a "normal" and a "tele" (smaller field of view) settings, and a "viewfinder" to accurately aim the light sensor, very useful in macro shooting.
3. It provides power ratio settings in manual (1/1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64). Without the Mecamat, the 45CT1 has only full power manual.
4. As I remember, the trigger voltage of the 45CT1 is about 180V. You can add a little circuit inside the Mecamat to reduce it to a safe level (you can see the label "7.5V" in the last photos below). I tried to add this circuit to the 45CT1 itself but there was no spare space inside to fit the components.
Used Mecamat 45-20 units pop up for sale once in a while. KEH currently has one LN- grade for only $8 + shipping.
Metz 45 CT1 and Mecamat 45-20, manual settings:
Metz 45 CT1 and Mecamat 45-20, auto settings: