RCA limiters abused with 230V, Aaaargh!

I got two BA-6A to check today. I think they have a history in Sweden at some film studio and now they are in Finland. The owner got them with euro style power plugs and...uh....I don't know who did this idiotic power plug swap and when, doesn't matter anyway, but they have been in use with 230V for some time. Somehow they have survived. Only one cap was dead and some wax had dripped out of a transformer. So, after I have re-capped and re-tubed them, what kind of problems could there be? Right now, or after some use?  I know signal has gone through them, so all trannies are pretty much OK.

How on earth have they survived without more severe damage? Some tubes were weak, but working. No shorts, no leakage, no open filaments.
One gets the impression that these beasts were made to last.

In worst case the high temperature could have affected the isolation resistance of the mains transformer. Quite unlikely because it has survived the higher mains voltage. You can measure it to keep your peace of mind (I always do that when repairing old equipment).