Well, Mike, not so fast!
Lee (46Sparky) sent me a private message asking for documentation to support my statement that the auxillary springs on a 1/2 ton were factory. I went back to my 1929-1950 Master Parts Catalog and realized I interpreted the listing for Utility to include 1/2 tons which it does not. Utility refers to trucks 1 1/2 ton and up. My old eyes misaligned the listing on the page. Furthermore, there is no listing for the bump stop for the auxillary spring which is shown in your photo. So these springs may be aftermarket. There is a listing for Advance Design 1/2 ton trucks with heavy duty springs which has one extra leaf (not a separate 6 leaf spring package).
Sorry about the (my)confusion,
Kent
