Interesting information about Hinnom and Gihon, JeffB.

With regard to the words about "Prince of Gehenna" and the likelihood of this later addition being intended to have exactly this "resonance", I do think it's important to recognise Ambiguity in Watt's own verses, especially when being aware of the political situation in Britain generally, and in Scotland particularly, at this time. The so-called "Radical War" isn't as familiar as, say, the contemporaneous Peterloo Massacre, but the repressive and coercive nature of the British State is not in doubt.

Put bluntly; it would be a very dangerous thing at this time, the time from which the original verses definitely come, to compose, to sing, let alone to publish a song which was openly pro-Bonapartist. Consider carefully these verses; get away from the modern assumption that this song is clearly sympathetic to Napoleon, and adversely critical of the "Victors' Justice" that saw him exiled to a remote rock with a notoriously unhealthy climate.