EDIT: For the fellow history nerds, I stumbled upon a rare photo of the building in use in the 1960s:
There's also a lovely aerial photo that shows the warehouse in its heydey (with a big 'J Irving & Co' sign on the front):
Nothing riveting but it adds a bit of context. And curiously it looks the fire escape only used to go up 3 floors or so, so the rest of the doors must have been added in the 60/70s.
Nice - always interesting to see old photos of the docks - the aerial one also shows most of the pumping station (bottom left) for the Canada graving dock.