Viotti indeed. According to the Nada Editore reference book it weighed 1030kg 'in ordine di marcia', compared to 960kg for the standard third series, which does not sound an excessive weight gain for a body that size. The final drive is 9/43 compared to 11/46 so obviously it was conceived as a workhorse. The book says 300 were built in 1960-61. I find the staid but modern styling attractive.