Sliding Door Mortise Lock Part #: 1060-1943

Hey everyone, the latch on my sliding door mortise lock doesn't extend any more and I was looking to replace it.

Is has an inside latch with 5-3/8" installation hole centers and a 45 degree dead-latch. The Mortise-Lock/pd/Patio-Glass-Door-Replacement-Internal-Locks/82-227 looks to be the replacement part but I'm concerned that there are no mounting screw holes on the sides of it like mine does.

Can anyone verify that the lock will come with side mounting holes or whether they're actually necessary? Thanks, in advance, for your help!

Doesn't look like the pictures loaded the first time.