Mortise lock with larger holes?

The spring mechanism broke - the mortise cannot be separated from the collar except for grinding (which I did). I need to purchase a new mortise with the larger holes centered in the mortise flange so it can be seated properly into the slider. The model number is 2260 - US patents 5,125,703 and D640,398.

I am comparing it against an aftermarket product that will not seat due to the offset screw holes and the pre-drilled receptacle in the door requires longer and wider screws.

Thank you,

Michael