dan; Thanks for posting the info on your truck. You have a rather, I hate to use the word 'rare', Studebaker truck. Decoding your serial number tells us-
Serial # M15-0110
M....series of Studebaker trucks built for production years 1941-1948
15...indicates a chassis rated at a nominal 1 ton (or in those days, a 'tonner'). This code also means this chassis had a standard 169.6 cubic inch, flat head, side valve, six cylinder engine hooked to a non-synchonized, four speed manual transmission. There were no optional engine or transmission choices.
0110.this number is the sequencial order in which this M15 came off the assembly line. The first 1941 M15 was serial number M15-001, therefore, your truck was the 110th M15 built. There were only 1230 M15's built in 1941.
There were three models of M15's built for production years 1941 and 1942:
> M15-20, most of these models were produced as pickup trucks with 8 foot boxes. The code '20' meant 120 inch wheelbase measured from the center of the front axle to the center of the rear axle.
> M15-28, this 128 inch wheelbase chassis was sold as a cab/chassis unit, a platform or stake bodied trucks from the factory.
> M15-52, this 152 inch wheelbase chassis was sold in the same configurations as the M15-28.
All of these models came standard with single rear wheels with 6:00X17 tires. Dual rear wheels (except for pickup bodied M15's) were optional equipment and a wide variety of wheel and tire sizes were also available as optional equipment.
All 1941 and 1942 M-series trucks shared a common, standard cab coded as a C2 cab. In Jan. 1942, all domestic truck production ended due to needs of the military with the outbreak of WWII.
In 1942, the Studebaker Corp. was called upon to produce 200,000 plus 2 1/2 ton, 6X4 and 6X6 trucks for military use. Studebaker used a modified C2 cab on these huge military trucks.
As WWII drew to a close in 1945, the US government allowed Studebaker to build 4000 M15-20 and M15-28 truck models for a new-truck hungry, domestic market. These 1945 M trucks were exactly as the 1941-42 trucks except for the cabs. These M trucks used the modified military cab (code C9) on these 4000 trucks.
After the War and when civilian production resumed in 1946, the 1941-42 models (except the M15-52) became the new 1946 Studebaker line of trucks with only minor changes. In order to distinquish the new 1946 M15's with the original C2 cabs from the 1945 M15's with C9 military cabs, the model code had an 'A' ie, M15A-20, added so dealers and buyers would know they were getting the domestic cab, not a military cab. Therefore, all 1946-1948 Studebaker M15's became M15A's. Yes, over the years, specifications changed for both standard and optional equipment for these vehicles.
Hope this answers some of the questions you have raised. Keep us informed about your truck. It truly is one-of-a-kind. I am not aware of an earlier produced M15 still in existance.