Bridge Gun Co., Bridge Gun Works, and Bridge Black Prince were tradenames used by Shapleigh Hdw. Co. St. Louis, on both Crescent and Belgian guns.
Your gun was made after 1898 and does not carry smokeless proof. Unfortunately, the initials you've chalked do not help ID the maker. Is it 'PLH' on the action?
Louis Muller was the Liege rep for Crescent, and would be a good guess
http://www.littlegun.be/arme%20belge/artisans%20identifies%20m/a%20muller%20gb.htm

Are there no marks on the action flats?