Locking mechanism.

We sell several different locks that have this same interior section. In order to narrow down the list of potential replacements, I will need you to remove this from the window and show me the exterior section, as well. It should be a fork or arm or something that engages with the tie bar system. 

Once I see that, I will check our inventory for a potential match.

These photos are exactly what I asked for, yes. Thank you! 

However, they do confirm that our company does not have an exact match for what you show here. The design of your lock is actually a little peculiar; I've never seen a locking tab with those pointed wings before. I'm not sure how vital that particular design feature is. It may disqualify all of our potential replacement options.

Assuming that it's not a vital feature, I would suggest looking at our 38-095 and 38-096 to start out. Carefully compare the dimensions we show for these two locks for your original and see what you think. You'll note that both have a very similar "U" shaped tab to your original, but they do lack those pointed wings. Despite that, they're our best options and I don't believe we have anything closer.

Alternate view of 38-095

Alternate view of 38-095

Side view of 38-096

View of 38-096 Hole Centers