The Alfa Romeo story started in Milan on 24, June 1910. That was the day a group of entrepreneurs and businessmen took over the Italian Darracq automobile company (based in Portello on the outskirts of Milan) from its French parent company, and called it Anonima Lombarda Fabbrica Automobili – A.L.F.A. The new company was formed at a time of economic and social change: the first plastics were being invented, Guglielmo Marconi received the Nobel prize for physics and Alfa’s competitors – Fiat and Lancia – were eleven and three years old respectively. The outbreak of World War One and consequent limited resources brought difficulties for the company. On 2, December 1915, it was taken over by the Neapolitan engineer and entrepreneur Nicola Romeo. The Portello plant, which employed 2,500 people at the time, was extended to handle military orders. At this time it was producing motor-driven compressors, munitions, aircraft engines and, from 1917, rolling stock.
In 1930, the Gran Sport was Alfa Romeo's fourth series 6C and their most capable sports-racing car. Fitted with competition bodywork, Tazio Nuvolari drove one to overall victory at the Mille Miglia and Giuseppe Campari repeated the feat in 1931. With its supercharger, the 1750 Gran Sport was an invincible race car, one with ample torque for its small chassis. The supercharger was a necessary ingredient that allowed the 1750 to be light, yet powerful, a characteristic that contributed to less driver fatigue and less stress on individual components. 
Now you'll need to find a little more Gran Sport history in order to get this cache location:
Price = Price(in pounds at the London Motor Show) of the Gran Sport Spider two-seater in 1930.
Length = Chassis wheelbase of the longer twin-cam Gran Sport Spider in inches.
Apply this information to find the coordinates:
N40 2X.XXX W075 0Y.YYY
X.XXX = 2086 + (Price)
Y.YYY = (Length)(76) + 97
Check with the Alfa museum to see if you're correct:
Bring your own writing device and be sure to put the container back as good or better than found!