Here's a promotional video for McCullochs “revolutionary” 1961 kart chassis that I found pretty entertaining. It shows the construction of the kart and explains the principles of it's design. Interesting how the front (spindles, steering, etc) is pretty similar to a modern kart but the rear (removable axle assembly, engine mounted directly behind the driver instead of offset to the side) is totally different. Other notible differences include the seemingly pointless front roll bar thing near the steering wheel and the seat integrated into the chassis, with padding of course! The emphasis on comfort as a selling point in addition to performance is another thing I haven't exactly seen in modern karting.