The youtube algorithm recommended me this brilliant channel from one of the stonemasons working on Lincoln Cathedral. Videos are short and accessible, and some really interesting stuff, both on the techniques used and some of the finds - worth a watch if that sort of thing floats your boat. The most interesting for me was using a hot lime based grout and pouring it down the back of a newly replaced stone to ensure that all the void behind the stone was properly filled - much smarter than just buttering the back of the stone and smushing it in with fingers crossed 
www.youtube.com
The Ginger Mason
Heritage stone mason at Lincoln Cathedral in the medieval city of Lincoln in the UK Stone carving, cathedral building with some geometry and history thrown in.
www.youtube.com