Sorry to hear about the trouble. Are you referring to the mortise lock? It looks like the one you have installed now isn't a match for whatever was installed originally. Could you tell me the distance between the two original installation holes, center-to-center? Can you also tell me the width and height of the large oval hole? That will help us find a possible match.
the distance from the top to bottom installation hole is 12"
the width of the oval hole is 15/16"
the height of the oval hole is 11"