Just take the screw out of the lid, heat a soldering iron (a real one) or a piece off metal Red Hot, hold it to the brass piece & warm it good & the epoxy should release. Cut & fit a new piece of brass & attach with screw. DON'T epoxy it until you are Sure it fits good, looks right, works, etc.
Take the latch bar off while you fit the brass piece to the lid & buttplate, as it's just in the way. Then fit the latch bar back into the lid & make it fit in the stock & latch.
If it doesn't quite latch going back in, file a little off the latch towards the operating knob. If you bungle it up you just get a replacement latch, no big deal. Don't force the lid in place. You may get it latched & can't get it loose.
Patchbox lids can be a PITA at times, especially wood ones. And if it isn't latched good, you go hunting & get ready to go home & all of a sudden you realize you bumped the latch & lost the dang lid, Someplace.
. You ever try to find a patchbox lid in the dark ?
Don't waste your time, just go back the next day.