Vinyl Tilt Latches
Hello,
If your dimensions match up to our 26-228 and 26-229, these could certainly be the replacements you're looking for. That being said, I'm not sure what you mean by the holes extending past the top shell. These latches are surface mounted, meaning they use screws to mount into holes in the sash frame, which appears to be how yours install as well.

Thanks for the quick reply.
What I was asking when I noted..."screw posts extending below [the] edge of [the] top shell (posts fit into holes in existing vinyl glass frame)" was...
The screws fit through "shoulders" which extend below the lower edge of the surface mount (seen in photos 2,3,4&5). These fit through the vinyl window frame, providing positive 'locking-in-place' of the latch and preventing any movement of the 'vinyl-on-vinyl' latch should the screws loosen slightly.
The "shoulder" on the latch-catch end (photo 5) also has a slot in it, for the "guide edge" of the latch (best seen in photo 1,2&3). None of the drawings of any of your latches show the assembled mechanism from the underside.
At one time our 26-120 and 26-121 had the option where the screw holes had extended mounting posts. Many customers found that they got in the way and had to file them down in order to mount flush on the sash surface.
Due to this and few requests for the mounting post, we discontinued them. The tilt latches without extended posts should still work even though the posts are flush now.
Lance