'31 Murray Body Number Plates

[Paul Woolner]

I have been searching for years, trying to find the proper format for creating a replacement Body Number Plate for my 1931 Murray Fordor. I know as an example, that it might appear as M-460-12345. My questions are: 1. what is the significance of the 460 ( is it assembly plant, body type) and 2. the 12345 I presume is just the next assembly line number, not the serial number of the car. I appreciate any information and pictorial detail you may be able to provide.
Paul