Probably some time in the 1960s.
Savage does not provide information on these rifles and none seems to be available anywhere else.
Savage 187N
$90-$100, depending on condition.
Hey i just picked up a 187N from a pawn shop here in NC, have not test fired yet but it has a refininshed stock, clean gun not much wear and tear around the chamber, i paid 60 buckaroonies for it, it also came with the original 4x springfield scope.
Hey check out this website http://www.e-gunparts.com/model.asp?idDept=235 Numrich Gun Parts, i found it while researching the feasibility of a sprngfld 187n, there are tons of models listed there, they may have what you need.
If you want to mount the scope directly to the barrel grooves you will need a 926587Redfield 1" Tip-Off Ring Mount 3/8" Grooved Receiver Matte Medium These are available at midway.com make sure you get the correct size rings to mount to your scope usually 1" Dia. You may need the tip off ring to be higher to clear the barrel mounted sight and the safety. The one above worked just fine on my wife's Springfield 187N. There's not a lot of info. out there on mounts for the Springfield/Savage line