Short answers, pulled from the story.
The lounge suit originated in 19th-century Britain as sportswear and country clothing. Its roots trace back to early modern Western European court and military dress, and the basic arrangement of coat, waistcoat, and trousers was already documented by Dutch Golden Era painters such as Jan Steen and Pieter Bruegel the Elder.
A bespoke suit is custom-made by a tailor from a pattern created entirely from the customer's measurements, giving the best fit and free choice of fabric; the process can take the tailor 80 hours. A made-to-measure suit modifies a pre-existing pattern to fit the customer, with a limited selection of options and fabrics available.
Brooks Brothers is generally credited with first offering the ready-to-wear suit, a garment sold already manufactured and sized, ready to be tailored. Haggar Clothing first introduced the concept of suit separates in the United States.
Wool suit fabric is measured by the weight of a one-square-yard piece. Heavy winter wools run at 12-14 ounces, medium three-season wools at 10-11 ounces, and summer wools at 7-8 ounces. Before central heating, wools as heavy as 16 ounces were used in suits; today that weight is reserved mainly for overcoats.
The canvas is a layer of sturdy interfacing fabric placed inside the jacket between the outer fabric and the lining to prevent the wool from stretching out of shape. Expensive jackets use a floating canvas, while cheaply manufactured models use a fused canvas that is glued in place; a fused canvas can permanently pucker along the jacket edges after dry cleaning.
The five-button Nehru suit was adopted by professional Indian men after independence as an alternative to Western clothing associated with the former colonial regime, and was made from khadi to support local textile production. During the 1960s, the suit attracted attention from the British mod subculture through its use by The Beatles.