Lewyt went bankrupt around 1962. The electronic models (with power nozzles)ran on a low voltage system which used a secondary winding in the motor and grounded through the body of the machine. Unfortunately it had a tendancy of shorting out and giving the user a shock which resulted in a number of lawsuits that bankrupted the company. Their assets were sold off and Shetland Manufacturing Corp. bought the rights to the name and the parts in the US. They made a different style of Lewyt right up to the 80's (someone else has the name now and it was out as a very cheap machine around 2000). At the same time Holland Electro in Holland bought the design for the big wheels machines and produced them, with their own parts, in Europe untill the late 80's. I've included a picture of one below. Guess thats the history in a nutshell.
Doug
PS: Incidentally the European machine was called a Holland Electro Toppy. The picture is courtesy of a friend (and fellow collector) in Belgium