Multi-Point Striker 89-030
Thanks for posting. I've found installing a screw in that center hole can essentially do the same job to make sure the center button on the mortise lock can engage properly. Another thought would be to pack out the keeper with washers to ensure it 'projects' far enough to interface with the lock correctly. Honestly though, depending on the measurements of your original setup the lock and keeper may work fine as is. Worst case would be to consider the other striker this type of mortise lock can work with, the adaptable 89-036; but I don't think that would be necessary unless the alternatives I presented don't work. Let me know if you have further questions.
You're welcome! Please feel free to reach out if you needed anything else.