Charle Daily is not a Browning but a Browning design. They were made by Miroku in Japan. Use the Blue Book of Firearm Values or take it to a gun shop for appraisal
The value of a Charles Daily 12 gauge semi auto shotgun is between $200 and $500 depending on the condition. These shotguns were used extensively for sport shooting and hunting.
What is the value of a 12 gauge Browning shotgun serial J68824?
1000 USD
$350
Basically impossible to value a weapon with just the gauge and sn.
If you mean a Browning B-2000 12 gauge shotgun then the value would be 495 dollars for a shotgun in the condition you describe.
Not a valid Browning serial number.
You will have to call Browning with the serial number to find out.
Browning never made a Model 51 shotgun.
http://www.browning.com/products
Use the link below
100-1000 usd