Old houses have old doorhandles and mounting plates. In my case I have them in bakelite. As replacement parts they are either very hard to get, or very expensive. I Fou bout it is much easier to design and print them myself. And when printed in ABS black, it is even hard to recognize they are different from the bakelite ones.

Of course they have to fit the doorhandles size. But in this case the dimensions and sizes are pretty standard. The design is an exact match to the original bakelite door handle plates.