Marvin sliding door hardware
Unfortunately, we haven't been able to find a good replacement for this handle set. If it's Marvin brand, then I am afraid there's a good chance we won't be able to get it. They have exclusive rights to a lot of their hardware and very often won't allow us to supply.
The only option we may have for you is to use a surface-mount set like our 82-005 as a replacement. This has its own built-in mortise, so it doesn't depend on any mechanism inside the door. That feature allows it to work on just about any kind of sliding door. The problem is it won't really look as nice, and you'll have a useless mortise lock still in the door. Otherwise, your best bet is to try to get a hold of Marvin directly. Sorry we can't be of more help, and good luck with the repair.