Locking Handle for Sliding Glass Door

Outside handle. Threaded screw boss standoff that secure the outer and inner handles have fatigued over time and broke off the casting. Several years ago I machined up 2 replacement threaded standoffs to secure the handles to the door. With the constant opening and closing of the door, the aluminum casting is cracking from pulling on handle. 
I don't know if I can buy just the outer handle and lock or if there is a complete assembly I can replace.