"What i'm afraid of, is a shorted deflection coil and if the case, how to obtain a spare. Were scan coil sets more or less similar across the Watchman family?"
No, there were several different tubes, each having it's own distinct yoke. The good news is that the first version of the tube with the flat phosphor surface (rather than curved) uses electrostatic deflection for one axis, so the problem may be as simple as a poor connection between the edge connector and the tube. See my pictures in the thread "A Little Flat Tube Fun"
http://www.videokarma.org/showthread.php?t=246309
jr