Your pic is small and grainy.No detail.Those H+R's were nicely done.As I recall ,it is an FN commercial mausr action,a hammer forged barrel you can see the swirl on,and a light bbl at that.
It looks like you are missing the magazine follower.It hooks on the leaf spring and goes in the box.Brownells,maybe.There are a number of routes to find ione,they can be found.
The latch? Couldn't see.Pretty robust and simple.
I think there might be a little danger of doing more harm than good.Its a nice rifle.Maybe ask your friendly local gunsmith for some help.
Sometimes fixing it makes it a lot harder to fix.