Deflection coil/yoke needed - any ideas on where can I get it?
First you have to know what kind of standard is the graphics card: MDA, CGA, EGA, RGB, RGB Sog, RGBS, RGBHV, YPbP, YUV ....then you buy a converter to DVI or VGA and buy a new LCD monitor. 

You can make a spacer or weld a nem holder for the LCD that can go into the existing case.