I needed to replace the mortise lock on a wooden patio door, so I bought another ERA brand one online hoping it'd fit without much adjustment.

The lock fits just fine but the issue is the plate that covers the lock, and the keep.

The doors have rebates on both edges and overlap, the keep and plate are designed to fit this rebate. I thought I could use the old ones on my new lock but although the lock has the same basic dimensions the layout is subtly different such that the old ones won't fit.

I need to order a set of the bits required and am wondering what they are called to help find them online?

This photo shows what I'm talking about:

https://www.dropbox.com/s/8tn0qxl2sj...43115.jpg?dl=0