Two undated card photos of the Fish Quay, North Shields. If you look at the second photo i'm sure that's a young "magoonigal" taking notes (see red arrow).
Good detective work Ron. However 3 of those you mention had single cylinder engines and therefore likely to have had single boilers and single funnels. The exception is GAUNTLET and she has the added advantage of being a John Dry tug which would be a match for the funnel colours. Maybe? Could even be a Very Maybe?