Left hand latch for bay window

Thank you for reaching out to us. I'm afraid I couldn't cross-reference the numbers given here. Can you upload some photos of the latch in question? We'll do our best to help from there. 

Thanks for the photos! Your casement lock reminds me of the Truth Lock Assembly; although, it is just a bit different in style. The left handed version of this part is the 38-099 LH Truth Lock Assembly, the right hand lock is the 38-100.

To confirm that this will be fit for your window, carefully review and compare the dimensions and design.

Dimensions for 38-099