What size are the drivers on the USRA Light 2-10-2

[blwfish]

What ACTUAL size are the drivers and spacing on a USRA Light 2-10-2 model?  The prototypes are 57" and I'm considering building an unrelated model on top - but the B-1 prototypes used 63".

[ebtnut]

For a ten-coupled mechanism with 63" drivers, I would try and track down a Penn Liine/Bowser PRR I-1.

[electrical whiz kid]

EBNUT;
I agree-not only is the assembly correct, but it runs like a Swiss watch.  Trouble is, try to find one. 
Rich C.