Chevrolet with Thornton bogie, anyone?

[gordon]

Leafing though my pile of manuals, always a dangerous thing, I ran across an illustrated Parts List for a truck I've never heard of ?

Chevrolet 4103 Special Heavy Duty Chassis with Cab

also

Thornton Dual Tandem Drive Parts

and

Bendix Vacuum Power Brake Parts

Issued October 15th 1940

Revised Feb 1st 1941

General Motor Overseas Operations
1775 Broadway,
New York

I can just make out a Supply Mech stamp on it too, looks like 2011/9/1

I'm familiar with the Thornton Bogie on the Dodge WK60 series, and I knew that you could get them on other makes, but wasn't aware of any Chevrolet supply.

Anyone know about these - David, Pete?