Before Duryea, Where Did Topps Print Cards?

[toppcat]

I had been thinking that the cards printed by Topps were mostly done by Zabel Brothers in Philly from 1951-64, then barged or trucked to the Brooklyn plant where they were assembled into packs with gum and wrappers made in Brooklyn. But Sy Berger's comments in the Great Flipping Trading and Baseball Card Book (sic) indicate most of the printing was done in and around Brooklyn, at 4 or 5 different plants before the move to Duryea concentrated everything in one building.

Zabel certainly seems to have done some printing for Topps based upon comments in some TS O'Connell articles of late (notably on 62 Green Tints) and also from discussions with a few other collectors but Berger's comments don't seem to support this. Was Zabel then the sub contractor for extra print runs with an occasional third subcontractor located in upstate NY? And what of the 1954 BB cards printed in Baltimore?

I'm going to try and put this all together in more coherent fashion but any insight is appreciated!