At Wigan Folk Club last Thursday, one of the members showed me a page pulled out of a magazine (sorry, can't recall which one), which had a newly-discovered verse to "Dirty Old Town". Apparently, Ewan wasn't happy with it originally, so it wasn't included in the final version. It should be the 4th verse, and the copyright was credited to Jean MacColl. I thought I'd be able to find it somewhere on the web, but can't trace it so far. Here's the verse as I copied it from that mag:

Moon of steel in the cloudy sky
Silver skin on the roofs of the mills
Stars are sparks from the chimney stacks
Dirty old town, dirty old town.