This belt buckle should end up customizable (hopefully with ShapeJS).
You will be abel to upload a black/white image you want to be engraved or cut out.
There is also a version for metals but because of different requirements it also needs more material which results in a more expensive product.
But check out for your self...
6.1 w x
4.15 d x
2.402 w x
1.634 d x