PGT Window latch

I'm not sure if your exact latch is made anymore, but our 38-036 is very similar. I would start with this and see how well it matches up to your original hardware. If I were you, I'd try to get a hold of an undamaged version of your lock to use as a reference. See if the lock on the other side of the window is still in good condition, or from another window in the house.