Fox Collectors

Now that I know when and where it was built, any ideas as to the increase in value (percentage wise) having the second barrel set would add??

I have a sterlingworth (serial 142090) with 2 sets of barrels and fore-ends that all have the same serial number. However, the 30inch set are stamped Utica, NY and the 26inch set say Chicopee Falls, Mass. When the heck was this all made and why would the barrels be made at two differnt locations. Th...