My uncle (who wasn't as posh as you and lived in a poorer part of Altrincham:D) often visited the gasworks to buy sacks of coke. I didn't see any trains but I can vaguely remember the tracks in Moss Lane.

My grand mother always said she had some pictures of the loco on Moss lane by where the shirt factory used to stand.
According to her, the loco had a bell fitted, I suppose that this was needed on a tramway.