I've been doing a bit more research on the 40 horse team ( you knew I couldn't leave it alone, didn't you). It was, according to an article in Billboard Magazine, June 28, 1952, driven by Jake Posey. He did not stop at 40 horses: he managed 52. Jake Posey was boss hostler for the American Ben Wallace Circus, and had worked for Mr Bailey of Barnum and Bailey's circus in 1896, before the circus left for Europe. Jake Posey was contacted by Mr Bailey and asked if he could drive a 40 horse team. He thought he could, and moved to England. He practised first by driving 12 horses, and adding 4 each time. He managed to get up to 40, and drove in the parade in Birmingham.
To get over the problem of driving round corners when you could not actually see the lead horses, the boss hostler would ride ahead, station himself at the turn, and let Posey know what was going on. All went well until King's Lynn, whose narrow streets were tricky for a normal setup, let alone 40 horses. A policeman stopped the leading horses; the boss hostler was too busy coffee-housing to get to his station on the corner, and in the ensuing disaster, one horse was upended and Lynch, the hostler, ended up with a broken leg. This was not the end of the excitement for King's Lynn: the brakeman applied the brake over-enthusiastically, and the wagon took out the entire side of a local pub.
There's an account here by Jake Posey of taking out the side of the pub, which became known as Forty Horse Inn, it's thought. There's another snippet about it here. I'm still looking for definitive evidence to confirm.