http://macfaq.org/hardware/graphics.shtml#Q2.1.8
2.1.8 - I have a dead CRT in my Mac. What other Macs can I steal a CRT from to fix it?
The 128, 512, Plus, SE and SE/30 share a common CRT.
The Classic and Classic II (and their Performa variants) share a common CRT. The CRT itself is the same as that used in the Plus, but the yoke assembly is different, so swapping a CRT from a Classic to a Plus/SE/etc. or vice versa is much more difficult and complex than swapping from a Classic to a Classic II. Also, swapping yokes will usually necessitate adjustment of the analogue board to get the image properly centered and sized.