Who were Peter and John based on?

Back in the late '70s I worked for a foreign multinational. At big exhibitions its world-wide salesmen would gather. Their behaviour together was very distinctive - big voices, big talk, big gestures, big drinks, jokeyness but moving rather like boxers challenging each other. Deadly serious and punchy about sales targets and status. They strutted around like giants. Woe betide support staff who screwed up - an instant furious glare would be the least of it. They were intimidating. It was the strange pack behaviour of Alpha males forced to be in each others company. I always believed that they were unique. Until that is, the appearance of universal salesmen, Peter and John, variously putting Uttoxeter on the global leisure market map and negotiating a merger with Romecorp.

A decade and more later, to my complete amazement, for the first time I watched Hugh Laurie's Peter and saw a complete detailed synthesis - with a 50% exaggeration mark up - of these salesmen who I'd thought were both unique and inimitable. So where did Fry and Laurie see the originals? I'm guessing it had been in hotel bars and in conferences. I still marvel at Hugh Laurie's impersonation.