Look at this sites referencing for that chassis and refer to its The Riders Volume 17 changes 17-7 and then refer to the,
Riders Volume 18 changes 18-8 located just below it and you will see a couple of references to some resistor and capacitor
changes, along with the use of a different oscillator coil. Then there is the difference in possible use of a different tube type in
the oscillator mixer portion.
Also there is referencing to the RC-1011 chassis and itís A and B versions.
All in all I donít think that it would make a hill of beans on consulting the general 56X chassis schematic, unless you then found
a specific difference in those areas, and were wondering about those parts / changes being different.
The most proper solution would be the consulting of the actual RCA service info for those chassis, and some further involved
researching on it, while I find the availability of any of those older RCA manuals ( actually sheets) as RARE as the extra fingers
coming off from my elbow. . . .lol.
73's de Edd