Let's start at the top. What is the action: double barrel, single barrel breech loading, self-loading (semi-auto), or pump action? What markings are on the gun (i.e., model name/number, serial number). Does it have a vent rib? What choke? What is its condition ("unfired" means very little, since all guns are proof fired at the factory). Do you have the box and papers? All of this info is necessary to even make a guess over the internet.
If it truly has not been fired and is oiled and blued,probably around $500 to$600.
shotgun
what is the value of 12 gauge skb double barrel ithaca 1900 model
The value of a 12 gauge featherlight shotgun is $800.00 bucks canadian.
300.00
Hunting quail or trap shooting
100-400 USD
The Ithaca model 66 single shot shotgun that was made from 1963-1978 was offered in 12ga,20ga and 410 gauge only.
Contact Ithaca for a manual
Remove stock from shotgun
From what I understand, its a big 10 gauge shotgun, more specifically a shortened police variant of the Ithaca Mag-10.
$600 all day long