Latch no longer clicks together

We sell replacements for every part you show here, but I'm not sure if that will solve your problem. I would play around with it a bit to make sure the mortise box inside the door isn't the problem; this is a little metal box containing spring mechanism that keeps the latch taut. If that broke, then you need to contact Pella directly.

Otherwise, see our 83-123 handle and 83-115 latch.

It is not, unfortunately; at least, not by us, anyway. We've tried our best to get our hands on it but to no avail. You will need to contact Pella directly.