Both my father and mother worked at Waterlow's the printers during the 1930's in the London offices.
Recently I tracked down my half great great uncle (my great great grandfather's son by a second wife), and in 1911 he was a printer in Maidstone and then I suddenly found him enlisting in the army from an address in Dunstable. I then found his marriage in Bedfordshire, and when I looked back at his wife when she was with her family in the 1911, I saw they were all lithographic printers, in Waterlow Road, Dunstable.
I am ashamed to say it took a little time for the significance of the name of the road to dawn on me (despite it being a long time family story about where my parents met).
Then when I googled Waterlow's I found that they operated in Maidstone and in Dunstable and in London too. He'd evidently moved from one works to another.
If you ever do find anything else about Waterlow's, Plummiegirl, perhaps you'd add me to your list of people who'd be interested?
Incidentally, my father (seen in my avatar) was a Conscientious Objector in WWII, and when he announced that to Waterlow's they promptly gave him the sack (he spent the war in the ARP). My mother remained there, but declined to print the bombing maps they produced, and they gave her the sack too. She was a VAD.