Well, I remember that it had the safety on top behind the "cocked" indicator that you slid left or right with your thumb to expose a red or a green dot.
Regardless, the idea of either the bolt being gummed up or the sear/striker being broken are probably spot-on. I'm leaning toward a gummed-up bolt, because the problem came on gradually over a period of time rather than all at once.
As a young kid, I was good about keeping the barrel clean, but I never recall giving the rifle the detail cleaning it probably needed.
Thank you all for the replies.