FIC was an importer. 50-100 maybe
Firearms International was an importer, now out of business I believe. It is unlikely that they would have actually marked the gun with their name before these markings were required in 1968. There are probably other markings that may identify the actual manufacturer. Double Action refers to a revolver mechanism and I have no idea what you mean by a doubleaction trigger on a rifle.
it is 114 =[)
50-100
Stevens 12ga. /mod dhead naught
50-100 or so
5-50 USD or so
THey were made by crescent firearm company.
10-100 USD or so
50-300 usd
Yes, just simply buy a double trigger and double trigger guard, open up your marker, remove and replace the old trigger and trigger guard.
Some parts interchange, but most do not.
Ask your local gunsmith for help.