I've replaced both on my car with a different version. One broke and rather than drill the broken bit out I got ones with two screw holes . Located exactly over the originals. Holes drilled, thin, clear gasket cut to shape and stainless screws.
Get into the habit of releasing before roof lift and replacing as the last action. Basically first and last actions.
I also lightly grease the mechanism on the rear catches to help
I think I got the new bits from Woolies.
