Topband: Checking vacuum in vacuum relay

[Guy Olinger K2AV]

Have noticed a craze around two of the connections coming out of a
glass 4PDT (Jennings RB4A) that I was getting ready to use.

If one does not own a megger or other voltage breakdown testing
instrument, is there a way to tell if there is a vacuum or air on the
inside of the relay, other than to go ahead and install it and see if
it breaks down.

It will be subject to 10-12 kV p-p in normal use, rated for 18 kV.

Or should I just toss it based on the description I've just given. No
actual experience here with that kind of high RF voltage on these
things.

All punditry on the subject appreciated.

73, Guy K2AV