"London's first professional undertaker, William Boyce, opened shop in 1675. William Russell, painter and coffin maker, linked up with the College of Arms in 1689.
"Funerals had become big business..."
About 1/3 of the population died well under fifty. The death rate among people of all ages was higher than it had been a century earlier."
Pages. 108-9 1700 Scenes from London Life.
"After coats and vests came in, the rules of mourning required the diagonal sash worn over the coat to be of dull silk, black to mourn a man and white for a woman or child. Hat bands too must show grief, in the form of "weepers", lengths of thin mat black or white silk falling down the back. The aristocracy put aside its silks and went into wool, in the first extremity of sorrow."
Page 119 Restoration London.
FWIW, my avatar is a fashion plate, original to the GAoP time frame, showing garments for lesser mourning... full mouring actually shows a gown somewhat like a cleric's gown...and the weepers are much longer...actually the more I look at it, looks more like just a long black cloak.