The answer to the question....

[Angelo]

....who designed the Lambretta GP?

"A trimmed and restyled front mudguard was fitted which all combined to give a sportier image for the new model. Ink splats (supposedly due to an argument when Bertone threw his pen down on the plans after an argument with Innocenti, over trim colours) were the main logo, except in the UK where chequered flags were used to go with its Gran Prix name"


Bertone was/is a designer that has worked for many car companies the most well known probably Ferrari, on a low point was the redesign of the Lada.

[jbcollier]

The chap I was thinking of was Leopoldo Tartarini, the founder of Italjet. He worked with Ducati on most of their drop dead gorgeous bikes.