[Phono-L] Take numbers on electric Columbias

I'm a little embarrassed that I don't know this, but not too embarrassed to ask. In looking at the records that were included in the set of four Bubble Books that were recorded electrically, I'm seeing the matrix number in the wax along with a set of numbers, of the form "number dash

[Phono-L] Any information about Columbia building no. 77?

I've just posted some blueprints for a proposed Columbia record factory building in Bridgeport, CT, labeled "Building No. 77." You can see the blueprints here: