That right there is the legitimate fix! As long as you don't cut into the flat itself it's a perfectly safe fix, probably take a bout 2 minutes.
Go to the hardware store and buy a 'fine' mill bastard file, grind the teeth off of one edge to make what's called a 'safe edge' and you won't even have to worry about cutting into the flat!
Both of those safeties could be made to work in less time than it takes to go online and order another receiver but hey, it's your money!