Sound like a Philadelphia Arms Co. Fox double. They were in business November 1902 to about October 1906, but were probably only actually making guns in late 1904 and the first half of 1905. Ansley left Phily Arms Co. in December of 1904 and incorporated the A.H. Fox Gun Co. in April 1905.

I think you have one too many digits in that serial number. The numbers I've recorded for Philadelphia Arms Co. guns run from 59 to 1845.

http://www.foxcollectors.com/philadelphia%20arms.htm