What model name does it say on the CFC certificate? I have listings for 47E, 47SL, 147etc etc, I'll type what it says verbatim:
Model 127This was Merkels finest sxs shotgun. The sidelock action featured full coverage fine line scroll engraving of the best quality.
exc:23000, VG 17500, good 13500,
Model 47E
Same as above but fitted with ejectors. Offered in 12,16,20 gauge. Supplied with fitted luggage case.
NIB 4500, Exc 3200, VG 2100, Good, 1200
Model 122Features the same specifications as the above models but has false sideplates. This model is fitted with ejecctors and the receiver is silver grayed with fine engraved hunting scenes on false sideplates, engraved border, and screws.
NIB 5500, Exc 4200, VG 3000, Good 1900,
Model 47SLSame as above but with engraving in place of hunting scene
NIB 8200, EXC 4200, VG 3000, Good 1900,
Hope this helps a bit. Its from the 2009 Gun Digest book of Guns & Prices. 4th Edition.
At least it can give some comparitive values. They are always only worth what someone is willing to pay, but a well advertised top end gun like your pieces should get you a new top o` the line Quad with all the cup holders and gun racks.