Nothing much to add except the following:
Example: ZDM750R7500083
Z = Italy
DM = Ducati (GU = Moto Guzzi)
750 - Engine size - 750cc
R = All tri-colour 750 F1 bikes -all years it was made
M = Montjuich
LS = Laguna Seca and Santamonica
The remaining numbers (except Montjuich) are the build sequence that begins with 75 (which also probably denotes engine size.)
7500083 = the 83rd 750 F1 tri-colour ever made
Example: ZDM750LS-750096
LS = Laguna Seca and Santamonica
750096 = 96th Laguna Seca ever made.
Santamonica begins at LS-750303
Example: ZDM750M-016
M = Montjuich
016 = the 16th Montjuich ever made.
Note - USA models have a 17 digit VIN - which does not conform to the above protocol.