100-300 USD
A Winchester Model 12 in "GOOD" condition can be worth between $250 and $450+ depending upon barrel length, choke, gauge, and condition of the wood.
There is a ton of information on the model shotgun. A 1/2 page at least. The Standard grade 12 guage in V/Good condition is worth $400. The Featherweight version is worth $450.
This was the Scout Model. made between 1954-58. In good condition it is worth between $50-$65.
$175 to $230 in good and working condition
$350-$400 in excellent condition
The model 340 was made between 1969-1989. In very good condition it is worth between $85 and $100
I presume you are asking about a Marlin model 120 pump action shotgun. In good condition a standard 120 is worth about $200-$250. If you are asking about The Revelation model 120 that was manufactured for Western Auto Supply by Marlin, then you are looking at a generic model 60. Worth about $75-$125 dependent on condition.
It appears to have been manufactured in 1939; 6,271 of them were made that year. If it's in one of the standard calibers of that era, in good condition, it's worth $650.
Depends on condition, condition, and condition, from just good to excellent 500-1000.00
if in good condition its worth $200.00 to $ 275.00
In good condition, your '92 is worth about $700 if it is a standard sporting rifle. If "548" is the serial number, it is worth about 10% more. The fancy sporting rifles, carbines and muskets are worth more,
The model 342 Rifle, was made between 1969-1992. In good condition it is worth between $65 to $85.