Non-standard 2 inch backset Flat Mortice Latch Replacement Kitchens, doors, rails, stud, tables, chairs, stair cases, garden furniture etc... Find answers and ask questions here!

[Quaker]

I have 4 doors in the house that have the old flat latches with backset of 2” (51mm). I want to replace them with similar flat latch but the new standard backseats are 44mm or 57mm. As I am not able to make new holes on the door, can anyone tell me please whether I can get replacement latches of 51mm at all? If so where from? I have tried various online locksmiths and ironmongers without any luck at all. I would really appreciate your guidance and support.