The savage/steven model 65-66 was made from 1929-1945 with total production being 174,000 guns.
I am not sure about the "Buckhorn" part, but if it is the same as the Stevens (part of Savage Arms) 52B S-L-LR .22 caliber single shot bolt rifle it should date to the mid-1930s. This firearm was also sold by Montgomery Ward as a Western Field model 36. (To make things confusing, the Western Field model 36 referred to both a rebranded Stevens model 52B-62-83N and a rebranded Mossberg model 10. The Mossberg 10 was made 1933-35.) The 1934 Stevens parts catalogue includes the Stevens model 52B (see http://www.cornellpubs.com/Templates/StevensParts1934.htm), as does the 1938 Stevens parts catalogue. The Stoeger 1939 World's Fair Issue Gun and Sports Catalogue does not include the 52B, but does list the Stevens Buckhorn models 53, 56, 66, and 76. The website www.e-gunparts.com lists the component parts of the Stevens model 52B under the heading "Savage, Fox, Springfield, and Stevens." All of these were brand names used by the Stevens company.
Your stevens model 65/66 rifle was made during the years 1929-1945.
NUMRICH HAS PARTS FOR THE STEVENS 66B
THAT DEPENDS ON WHO IS BUYING IT.
There is the possibility that your Stevens model 66-B does not have one.Serial numbers were not mandated until 1968 by the GCA(gun control act).My records indicate that the Model 66 was made from 1929-1945.With a production of 174,000 firearms.
50-175 USD
The Gun Digest Book of Modern Gun Values, 9th ed, shows the Stevens No.66 with a used value of $75 to $80.
Thew old model 66 was made between 1983 to 1988. after that the model 66Rt was made from 1993 -1994 the model 66BX was made up to 2005 and the new 66 powermaster is new for 2012
These range in price from 30-60 dollars.
Try the auction sites, ebay, e-gunpart.com, do a web search.
The last year of production for the Remington model nylon model 66 was 1990.These rifles were made from 1959-1990 with a total production of 1,050,336.
The model 11 is a bolt action clip, the model 12 is a bolt action magazine tube, and the model 66 is a autoloader (also a magazine tube). The 11 and 12 were made from 62-65 the 66 was made from 59-89.