T207 WC3 or WC 4, chassis 8644701 up
T211 WC13, chassis 8676901 up
T215 WC21, chassis 8150001 up
Look here for serial number data;
http://homepage.powerup.com.au/%7Edjr/serial.html
... and a sequential listing of chassis numbers that will help to date it. It is a "1941 model" but in practice could have been made pretty much any time between September 1940 and May 1942.
It's one of the most common Dodge types and not particularly valuable, but if it does have the original T2xx engine and complete original body and cab that will maximise the value.
Gordon