Those are K frame target stocks. They’ll fit on an N frame, but the back of the grip fame will stick out near top. They probably date somewhere between 1973 and 1980.
You could place a trade ad in our classifieds. You might need to add a little cash, but smooth targets are popular.
Personally, I’d keep them and just buy a nice pair of N target grips. I’m sure you’ll come across a K frame in the future that needs a set of grips and you’ll have the perfect excuse to buy it!
Negative. Keep them as they will come in handy at some point and resume the search for some N's, but don't be surprised if they're more than $10.
Although strange things can happen... heck, look at the grips you've already bought...