I have the 18th edition- 1931- of the Kidder-Parker Architects' and Builders' Handbook. It has a few pages, including sketches, of the Gypsteel system, but no load tables. Here's a synopsis: The Gypsteel system consists of 2-1/2" thick precast gypsum planks reinforced with 3/16" cold drawn steel wire at 4" oc. The planks are 24" wide x 29.75" long; basically they span 30". The projecting wires of abutting slabs are twisted together tightly, then the rabbeted space between the planks are filled with a gypsum pour.
There are also 2" Gypsteel ceiling planks, reinforced with flat steel bars, that are hung from the bottom flange of the supporting beams. There were special pieces available for cladding the steel beams and girders as well. The entire assembly, with a 3/4" plaster coating on the underside of the ceiling planks, was good for a 4-hour fire rating in 1931.
Gypsteel roof planks could span up to 7'. Weights varied from 11 psf to 17 psf for the roof planks.
If you need the pages faxed to you, let me know.