I agree, but don't have enough info to know if the dimensions work out.
One of the links in the first post confirms your idea:
Quote
The SRW and C&C axles use the same housings and shafts, with the difference in width being in the hubs. The housings are actually identical except for the location of the backing plate flange. Drums & hubs are different, but backing plates, shoes, and wheel cylinders are the same) * The SRW and Van axles use the same hubs, the C&C and DRW axles use the same hubs; Though different, the SRW/Van hubs and the C&C/DRW hubs can be interchanged causing a change to the axles WMS...
C&C and dually brakes are the same.

So, start with a single wheel pickup axle, swap dually or Cab & chassis hubs (same thing) But, then what brake drums (and backing plates + shoes) fit the backing plate flange already welded to the axle?

Would need a single wheel axle to measure and test fit the different drums.
Or perhaps can figure from just the difference in hubs? here's a picture of single wheel and dual wheel hubs side by side http://www.pirate4x4.com/tech/billavista/14b_bible/images/brawler_hub3.jpg
If the single wheel hubs were traded for dual wheel hubs (on the single wheel axle) then a brake drum with a couple inches less offset/dish/height would be needed as seen in the picture.

If we could find the answer to that problem it may be better than the spacer I've proposed for the C&C axle (otherwise complete with all original parts).

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-