Window latch identification

Hello, thank you for posting! 

Please start by reviewing the style and dimensions of the 90-005 sash lock to see how it compares to your original. 

Alternate image for 90-005

The 90-005 takes #8 screws, but the length would be different from window to window. That depends more on the design of your sash than the lock itself, if that makes sense. My recommendation is to just reuse your old screws. Or, if you wanted new screws entirely, take one of your old screws to a local hardware store to get the appropriate length.