Sash lock
Thanks for posting. This sash lock is indeed a bit unusual. There's nothing odd about the 2-1/16" hole spacing, but that's an awfully big offset of 15/16". That, and the general style of how the throw protrudes, is a bit different than anything in our catalog. I'm forwarding this discussion to one of my senior colleagues, and we'll get back to you as soon as we can with further thoughts.
KW
Many thanks for your correspondence. I am afraid that I was unable to find this old Better Bilt lock set in our archives. We do have the 90-278 lock, which has screw holes that are 2-1/16" apart and a set back of 11/16". It won't have the extended keeper cover like yours. For a face mount keeper we have the 90-237. Take a look and see what you think.