Value of Browning Automatic

[joeyclimbing]

This 12 guage has a chquered straight stock and is old; serial no 11817. I took it to the trap range and it cycled nicely. It has a 28" barrel and has Fabrique Nationale - Liege stamped on it, together with Browning's Patend June 16, 1903. If anyone can direct me where to look for a value I'd appreciate..
My father bought the gun nearly new back in the 30s or 40s but I can't ask him because he died in '89.
Thanks!

 

[NZClaybuster]

The colour is important to the value.|
Black and silver most common, blue and green the rarest. Brown a little more common than green and blue.

2, 3, 4 5, 6 hundred and up

 

[davemccarthy707]

I am assuming its an Auto-5? Try the shotgunworld forum.