I have a Fusil Robust No 7 Side by side shotgun in 12 Ga. Looking to see if anyone has a gun value book that might list it. Made in France by Manufrance. Has duel triggers and ejectors (not extractors) It would appear to have been bored out to accept 2 3/4 shells (70mm). The barrel says 65mm (2 1/2"). Any help would be appreciated.