I have a 20ga LC field grade FW S (serial-3075*). upon returning from a hunting trip, I tore the gun down for a thorough cleaning. When I took the forearm off a screw fell upon the table. When I looked at the forearm I noticed that I must have lost one of the two screws when cleaning the gun while on the trip. Tje screw appears to be 7mm long. any info of a source for a replacement would be appreciated