This is something us Indian's have been unfortunate to find out.

Our stonemanship has unfortunately disappeared from lack of state support in the times the subcontinent was under foreign rule.

Over in Europe, when the Notre Dame cathedral burned down, ancient 13th century skills had to be revived to rebuild it. Even the lead needed to be made traditionally, noone else in the world except a small company in the UK who could. Ten tons of UK lead now adorns the roof.