BIBLIOGRAPHY
I finally added the bibliography of historical sources used to produce the car index.

FACTORY LITERATURE
In 1974 Post-Era Books compiled a collection of literature from the Duesenberg factory and published them under the same cover.  This is the source for "Duesenberg Ads", "Model J Instruction Book", and "Model J Specifications".

IMPERIAL MANUFACTURING
Marshall Merkes was once the owner the Duesenberg marquee, operating out of Los Angeles selling parts.  In the early 1960s he published a series of bulletins about restoring Model J Duesenbergs.  Some of those bulletins are reproduced here.  My dad only had issues 8 through 11; the first seven were provided to me in January 2015.

GEAR RATIOS
Lassiter Hoyle (1920-2015) provided the list of gear ratios.  He has always had the ability to calculate gear ratios in his head, and probably produced this chart from memory.  I used this chart to check the accuracy of odometer and speedometer on our car (and which rear end we have), but I had to come up with a formula to calculate speed based on the revolutions per minute (RPM).  The chart uses 4200 RPM exclusively, a figure chosen because it is used to specify the expected horsepower output (265 horsepower at 4200 RPM), but that's not very useful at normal speeds.  We have yet to drive our car over 3000 RPM, nor do we have any intention of doing so (that's almost 80 mph).  By the way, our instruments are the old style barrel type, and wobble enough to make accurate readings within 10% of the actual value impossible, but the they do prove reasonably accurate.

ZAHN'S LIST
Ray Zahn's list was made in 1968 and includes detailed ownership information for many of the cars.  Its primary shortcoming is that all chassis numbers are omitted; so it is sorted by engine number.

   The Duesenberg is one of the iconic images of the boom times of inter-bellum America.  The familiar Model J was called the "Mightiest American Motorcar" by its manufacturers at the time that it was built, and has remained a symbol of both the awesome power of the internal combustion engine, and the elegance that can be achieved in automotive design and appointments.

NEWPORT
All references to the J. Herbert Newport Collection refer to an inventory list of topical files containing information for each Model J car.  Each folder is labeled with chassis number, engine number, and the wheelbase length.  Several entries in the list, which is sorted by engine number, include information regarding engine and body swaps, and the names of famous owners.  The description for this part of collection, titled "Duesenberg Models [series]", states that some of the material was likely gathered by a friend of Newport's, and not Newport himself.  We can go further and state that some of the material was collected after Newport's death in 1947, because it includes some facts that occurred afterwards.