Many Degauss coils are on ebay.
That being said, Maybe a tool demag would be better if there are any magnetized higher carbon steel causing the problem.
Degauss coils generate low AC magnetic field that work on soft iron (shadow mask, deflection plates, grid supports, cathode assembly and maybe the mu-metal shield) at some distance.
Tool demag devices generate very strong AC magnetic field that work close-distance with a death grip until the tool is moved away and the field shut off.
For most of these, the on time is only allowed for ten seconds to avoid over heating.
We used to make a simple version with the coil from a two pole shaded pole fan motor, disconnected from the dovetail joints connecting it to the armature/shaded pole assembly.
Bear in mind this drastically decreases the AC impedance and will rapidly over heat.
Also the near-pole magnetic field will be very strong and should be isolated with 1/2' wood thickness.
Energize near the demag target, move away slowly and energize.