The resin one you can probably get away with dremel and necessary normal tools.
The stone one I think is not for d.i.y.
One possibility is a stone mason, maybe through a funeral directors.
Second, be nice and grovelly to a local water jet company, ( or an importer of said machinery who normally have a demonstrator machine. I got an importer like this to reprofile some brake pads that I wanted to use in my sports car that the compound wasn't available for.) it will take seconds after the machine is programmed.
Gary
Gary
It is easier to seek forgiveness than to ask permission
Rules are meant for the obedience of fools and the guidance of wise men