Hello I have a client with windows that are in good shape but the locking mechanisms no longer latch.

Hello there. If you need a new casement window operator, this should be either the 39-031 & 39-032 type, or the 39-155 & 39-156 type. The only difference between these two sets is the length of the link arm, so compare both with your old hardware to see what matches best. 

I must say, it's heartening to see snow in your photos! We seem to be a ways away from getting cold weather here, even in late October.