Do I have the 26-434, 26-387, or none of the above?

A home owner from Hartford, CT says:
We have newly installed Marvin Integrity windows for which we would like to have vent locks. In your experience,would either of the two parts listed above work as a retrofit. The 26-434 would have to be mortised so it could be flush mounted to allow the sashes to clear but there is only 13/32" before the glass so would there be enough room for it to operate? Meanwhile, according to the discussion on your site, the 26-387 only reaches 3/8 back. If anything, the face of the lower sash on the Integrity is a little farther back so, if the 3/8 dimension is correct, that hardware will not work. If it does reach back farther, while we have the 5/8" required for mounting, it still looks like it might be difficult to get access to install the screw posts. Would it be possible to mount the 26-387 using sheet metal screws alone, instead of the machine screws backed by the screw posts, or would that not be strong enough. Thanks for your help. Mark
User submitted photos of window hardware.
Profile picture of Dave Sr.
Dave Sr. from SWISCO responded:
I'm afraid I'm not too familiar with Marvin Integrity windows, but I know they have a lot of exclusive parts. You may need to check with them if they have a vent lock made for this window. I don't believe the 26-387 would work because of the side trim on the window. Like you mentioned, you could possibly use a type of wood or sheet metal screw, but the trim on the side of the window looks like it is contoured. you would need more of a square trim to mount the base of the 26-387. We also have the 26-434, which is made to be used with wood sashes. It may be worth considering. Take note of the clearance between the wood sashes, like you said, as well as the depth of the glass, and most of all you will need to mount the base on the wood part of the sash. Make sure you do not screw into the wide glazing bead shown in your photo as you could damage the glass.
A home owner from Hartford, CT says:
Hi Dave,

Thanks for your reply. The key questions are the dimensions. Is the reach back on the 26-387 3/8's? More importantly, can you tell me if the 26-434 can operate with only 13/32's between the glass and face of the sash?
Tx.
Profile picture of Dave Sr.
Dave Sr. from SWISCO responded:
I'm really not sure. The reach back on the 26-387 is closer to 5/16". If you were to cut the bottom of the lock, you would have a wider base and may be able to make that 3/8" reach. I'm afraid I cannot guarantee this will work, though.
26-387 : Face Mount Single Action Vent Latch Kit
Face Mount Single Action Vent Latch Kit
26-387
$16.18
VIEW >
26-434 : Double-Hung Window Opening Control Device Kit
Double-Hung Window Opening Control Device Kit
26-434
$48.45
VIEW >
How to install a Window Opening Control Device (WOCD) kit
How to install a Window Opening Control Device (WOCD) kit
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