Left hand window latch
Thanks for posting. These tilt latch might be our 26-243 (the opposite-handed version is the 26-244). This type of latch is very commonly seen; but remove an undamaged latch and compare to all the dimensions below to confirm. Let me know if anything differs.
You're right, that tab on the bottom is a little different. We actually did sell a version of this at one time whose bottom tab had that same orientation, but it's unfortunately not made anymore.
Our version should still work, though. The consequence of using the different style is that ours won't lock into place as nicely as yours, but that won't matter once the window is installed and in place. While the latch is braced against the jam, it will be tightly braced against the sides of the window frames, so it has nowhere to go anyway. It should still be okay.