On the flip side, lime mortar houses circa 1900 are great for putting
holes in, as easy as Lego.

You've got to be joking! My 1909 house is terrible for putting holes in. The
mortar and brick are so soft, it is hard to drill anything without whole
bricks disintegrating.

I can often get one in by turning off hammer until it is an inch in. After
that, the hammer is required to advance, and very careful and delicate
hammer can sometimes get deeper without smashing the thing.

Christian.