Russ,
Simply haven't drawn that yet, still trying to figure it out. Erecting card and photos not too clear, the equalizer is snug up to the top frame rail kinda obscured by part of the valve gear linkage (? nearing edge of current knowledge of subject). Or it could be there really is no equalizer between 2 and 3, that the spring hangers connect to the upper frame rail, I don't know, still researching, but frankly that's the way I'm leaning. And yes there is an equalizer between the 1 driver and pilot truck, haven't fully grokked those connections yet (most of the information is there, but haven't attained clarity yet).
With the dearth of C-21 information, I'm turning to other sources to help fill in the blanks, like the 1906 Locomotive Cyclopedia or roughly contemporary engines like the early K-27s with slide valves (17 x 22 cylinders compared to 17 x 20 for the C-21s) or the larger C class engines. Trying to follow common practices of the times, both 1900 Baldwin and 20s-30s-40s D&RGW.
And please let's all remember, I know just enough about what I'm talking about to be completely wrong!
But I'm trying.
More to come,
Mike