I have a quantity of old sandstone, in which I will be building a low-
ish garden wall. The stone came originally from a mediaeval church
window, but has since been cut down to blocks that one or two chaps
can lift.

For longevity, should I be considering using lime mortar in this
construction, rather than using hard cement around soft sandstone?

I've also got nice old weathered faces, and harsh machine-cut faces to
some of these blocks. Any ideas on a quick-ish method to soften the
machine-cut faces?

Cheers
Richard