Neons are used as spark gaps. Probably one for each cathode.
If the CRT arks internally it will be taken to ground instead of
hitting the driver transistors & killing them. The common NE-2
probably will fire at to low a voltage. You may have to find an
organ donor. Set will run without them but with risk.
Most newer sets have SG's built into the CRT socket on each pin.
The focus always looks different due to the high voltage on it &
they can cause troubles.
Other SG's are small white blocks ( Sony) or a pair of insulated
wires side by side ( old Zeniths).
73 Zeno
LFOD !