Royal Gun Works was a trade name on shotguns made by Anciens Etablissments Pieper in Belgium from 1905 to 1957.
By the serial #
What does this gun sell for?
1905
Impossible to answer without the serial number
This gun was made in 1989
Blue Book of Gun Values
If the shotgun is a hammerless double, it is a Baker Model produced in 1899 (per Dixie Gun Works, Ithaca Serialization Guide) That serial should be a 1926 production NID. sales@countrygunsmith.net
Try Midwest Gun Works.
Try on line auctions, gun shops, gun shows, pawn shops, estate sales, garage sales, MidWest Gun Works, Shotgun News, egunparts.
Lender's royal service # 117709
The value of any gun is based on make, model and condition. We cannot tell that from the serial number. You need a hands on appraisal. Take your shotgun to a reputable gun dealer or gun show near you.
The serial of you Parker shotgun did not print in your question. But to find a date by serial number, there is a Parker Gun collector website that has a list of serial #'s and date of manufacture. The website is : http://www.parkerguns.org/