I know this is an old thread, but people seem to have trouble finding info on these (or aren't looking).
I recently inherited one of my parents' Model 06's and have been doing some research as to the specifics.
Homestead-Service is a great resource for determining model specifics/differences and possible value.
Also,
WinchesterGuns lists 1906 S/N's on page 16.
This may have been covered, but I've come across several posts where people had the wrong years of production for their rifles based on the s/n, and I wanted to make sure they had more info at their disposal.