I'm scratching my head as to how the original owner managed to reverse-bias the power input. The thing shipped with the original power supply. Maybe he/she was working in the dark and grabbed the wrong adapter.
This is very likely, and you don't even need to be in the dark. If you have several power supplies with the same plug and the usual mess of cables, it's bound to happen sooner or later.
We can thank Atari for using a very common plug, reversing the polarity compared to the majority of other power supplies, and not actually including the reverse-polarity protection diode that's shown on the Jaguar schematic. You can almost see the marketing guy thinking "PROFIT !!"
Anyway, the regulators have been desoldered and the parts are in my shopping cart. Before I pull the trigger, I was curious if anyone has found other manifestations of using the wrong power supply so I have all my bases covered.
Beside the power supplies sections, I have never heard of another part of the Jaguar being damaged by a reversed polarity.