I don't think it's similar to the Metz 58 AF-1. But I do think you can use it with your K-x.
You do need a SCA 300 series module, however. An SCA 372 (for Pentax) is preferable, but not necessary. An SCA 300 module for
any camera with a standard hotshoe will work. I have a 45CT-4 and a 60CT-4. I use them with an SCA 300 module for Nikon. They work fine.
Except for the sync signal to trigger the flash, there is no communication between the flash and the camera. But you can just put the flash in one of 3 auto modes, put the camera in manual mode with shutter speed of 1/180 sec or slower, match the ISO and the aperture settings on the flash and on the camera, and shoot.
I don't know about your side of the pond, but here in the US, used SCA 300 modules are pretty inexpensive.
This is an example.
But first, measure the trigger voltage of the flash. I think it is safe, but you can't be too careful.