If you want an investment or something to tie up solid cash sell your crud and buy something propper collector grade.
Doing something battered up will never make it a collectors gun, it will still be a battered gun, but it might look a bit nicer.
If you want to enjoy the guns you own and shoot well with and feel they have earned the cost of restoration then go for it, they are your guns do as you like you may.
If they are poor guns, no amount of work will make them good, that old saying cant polish a * you know what.
