An excellent response to this post, thank you to all who responded. I did miss the reference to O’Brien’s Gold Medal brand in David Hughes book.
I believe O’Brien bottled lagers from Allsopp, Wm. Younger and Red Tower. I would guess that this Pilsener was brewed by Allsopp.
Here is the Gold Medal brand label from Phoenix Brewery in Amersfoort, courtesy of Onno. I thought you might be interested in the design similarities