Frequently asked questions.
First two pictures are of common household white silicone glue used to secure the neckboard to the picture tube socket. This was done to keep the neckboard from scooting off during shipment from the factory. Wells-Gardner and a few other monitor makers did this since the monitors were shipped worldwide and frequently get bounced around. Not every monitor manufacturer did this though. If working on the monitor for the first time and you need to remove the neckboard you must carefully slice through the silicone glue so you can scoot off the neckboard without damaging the base of the picture tube. You do not reglue this.
The last two pictures are of the hard glue (not silicone this time) Wells-Gardner uses to secure tall or heavy electrolytic capacitors to the circuit board. Again, it keeps the components from breaking loose during shipment. No need to reapply glue here either.