100-400 USD
870 20 ga stock will work on Rem 760 7600
Depending on the condition it could range anywhere from $650.00 to $950.00
20 ga = 650.00 dollars in good condition
100-300 USD depending on condition
Yes, after some time of discontinue, Remington returned to building a 16 gauge 870. I will warn you that ammunition can be difficult to fine. Keep that in mind..
The pardner design is astoundingly similar to the Remington 870 design. Search for Remington 870 dissembly (or cleaning); I believe there are several Utube videos.
If this shotgun is indeed "like new", a Remington 870 of that vintage with a plain barrel would run around $225.00. With a ventilated rib.....around $450.00.
Compare letters in front of receiver below and behind choke to these on this page. http://www.remingtonsociety.com/questions/BLACKPOWDERX.htm
100-200 USD
Since there is no one Remington 20 g model, there is no one answer. If the owner's manual (available free thru the Remington website) does not help, take it to a gunsmith.
You can contact Remington directly,and use the customer service site to E-mail your shotguns serial number and letter code found on the barrel.They will contact you with the year of production.