You might give Tracy a call at Graco 479-787-6520. He should have an extra or two around. Graco also has drop in replacement hardware for Brownings if you want to get rid of the screw completely.
My factory Browning comb always wiggled, and I needed more adjustment so I had the replacement parts installed.
My factory Browning comb always wiggled, and I needed more adjustment so I had the replacement parts installed.