[Heathkit] HW-16 question

[lynn simons]

Hey Guys,
   I am in the process of restoring an HW-16 and found the neon bulb that is used in the sidetone circuit was broken. The schematic just lists this as a "neon bulb" as does the parts list. In the assembly instructions it mentions the bulb has a red dot on one side and it should be installed on the circuit board with the red dot on the side depicted on the silk screening of the circuit board. The sidetone circuit is a relaxation oscillator and my understanding is that I can just replace this bulb with another neon bulb like a NE-52 or such. Is this correct? Also, I didn't know that neon bulbs could be polarized such that they had to be installed in a certain orientation. Can someone elaborate on this for me?
Thanks,
73, Lynn,  KJ3V