[morzh]

These are the Y-caps, the filtering of the line to the chassis.

1. Make sure you only use Y-rated capacitors. This ensures you don't get killed, and the caps don't become "killer caps".
2. Safety standards were different back then. The leakage, or the touch, current depending on what standard is applied can be required not to exceed 0.5mA to 3.5mA.
10nF makes it 1.28mA peak which is 0.9mA RMS. Won't kill you but will be sensed if you are grounded. 15nF will make it 50% more.

I use 10nF ceramic Y-rated caps.