Like I said before, very well done. I can say with most certainty that the body was not put on a 1929 Chassis in 1929. It is just not something you would see that early. It is possible it was done in the late 30s as the front styling is indicative of that period. While the nose is reminiscent of the Swiss builder Graber, the tail is very English. So to answer your original question, Yes it is a custom Marmon. However, the body was not put on the chassis originally but I guess it's possible it was done before WWII. There are pictures in period of almost all bodies produced by the larger builders. Finding a prewar picture of the car would help a lot.