Don't know where it started but I got my first in 1971, probably at John Colliers (the window to watch!) in Rochdale and then later at Chads, a bespoke tailors also in Rochdale.
It was part of the craze that the suits had more and more extreme features in order to out-do others, more and more buttons, pockets, longer vents etc.
Definitely a Mod thing, whether or not you were into Northern.
Happy days!