I'd like to see pics of what you got going on. From the sounds of it you may not need to replace the housing. If it's just the corner edge near where the cap mates to the housing I would say fix the threads carefully so the adjuster rings turn freely and easily and you just might be ok. But pics would be better for making that call.
![Yes Nod :yesnod:](https://board.marlincrawler.com/Smileys/marlin/yesnod.gif)