Just translated this from wiki.....................
"The first model, designed by the Italian coachbuilder Scattolini and equipped with the same engine 125 cm3 Innocenti Lambretta , was born on the initiative of the Italian entrepreneur Carlo Lavezzari and was presented as a prototype at the Paris Motor Show 1966 which aroused the interest French entrepreneur Henri Willame , Director of Lambretta France who commissioned the production constituting Lavezzari now Lawil , an acronym of the names of the two partners of the firm.
The small car began to be marketed in Italy since 1971 under the name of Lawil Varzina (named after the town of Varzi ) undergoing profound changes to the mechanics , motor, originally Lambretta 125cc was replaced by a BCB 250 cc , also the wheels replaced the previous 10-inch by 8 .
At the time, according to Italian law the so-called microcars could not own more than three wheels so the Varzina , with four wheels , was the smallest car for sale in Italy [1] .
The same car was marketed in France, where he was considered rather a quadricycle , as Willam Farmer and imported the following year (1972) in England by the coachbuilder Crayford .
The sizes were very small : the length of the prototype did not exceed 1.78 m . with room for two passengers and with the mechanics of Lambretta engines and two-stroke single-cylinder 125 cc and 175 cc , then the car was lengthened by 27 cm in 1969 and in 1980 , shortly before the cessation of production of an additional 20 cm ."
I can only conclude that they also used a 125 BCB as well or that my car had a 250 single BCB because it was definitely marked BCB and definitely a single cylinder. Strange!
Also interesting that they changed the wheels at some time but I didn't really understand that bit.