Sliding door lock broken

Hello there. We don't carry that housing that surrounds your mortise lock, but the lock itself looks like the 82-218. Please compare. Does the lock work fine? If you try and throw the latch, does it fully extend? If so, you might want to try packing out the keeper on the door frame that it is supposed to latch onto with washers, to see if that improves the connectivity. If the mortise lock is impaired in any way, however, then replacing it is your best bet. Let me know if you have questions.