These are called X or Y caps today, X cap connected across the power input lines, Y cap connected from line potential to safety ground. Used for EMC.
The rating is 400V AC nominal, but up to 4kV impulse rating (e.g. during line burst or surge events). The caps can stand a limited number of these events.
They look like ceramic ones, check if the coating is OK (no cracks on the body, some smallish cracks at the leads would be OK) and don't replace them if they look OK, they don't degrade like electrolytics, and they aren't the well known exploding RIFAs.
Otherwise you'd have to figure out if you need X rated or X rated caps by reversing the schematic (my guess would be Y), because they are critical for safety.