DF you will notice that ALL Navajos and Chieftains have a serial number of 31-YYMMxxx
The YY is the year of manufacture and the next 2 digits indicate the model.
Check out VH-IXP or VH-WAD or VH-NMP for example
31-80 52 185
31-75 52 018
31-78 52 149 respectively
...so there ya go!
Last edited by Horatio Leafblower; 29th Jan 2014 at 10:20.
Reason: Cos I checked my own work and I was wrong!