don't worry,
as long as you are careful how you handle the monitor whilst moving it,paying particular attention to the tube neck,you won't have any problems.
the voltages on monitors are only dangerous when power is applied and its like anything in life you just need a bit of common sense(i.e you would not put your hand in a food blender when its running to clean it)
just always make sure you have room to work and a sturdy table near the cab to place the monitor on if you need to keep moving it out the cab.
only apply the voltage and signal when you have double checked everything is installed correctly and safe.
the voltage you worried about is the eht,unless you pull the anode cap off the tube whilst voltage is applied then you have nothing to worry about