This is a photograph that I took at the Donington Park Museum in October 1989.
It's a 1932-34 Alfa Romeo Tipo B and the book Great Racing Cars of the Donington Collection has this to say about it:
The car was based on a very slender
channel-frame chassis, carrying a similarly slim body only 26 inches wide. The
cockpit sides were low-cut to give the driver elbow room, and the basic
eight-cylinder engine was developed to a 2.65 litre capacity with enlarged bore
and stroke. Two small Roots supercharger were used, and the power was boosted
from the Monza’s 165bhp to 215bhp a 5600rpm. Drive to the rear wheels was
unique, with the differential on the back of the gearbox instead of in a rear
axle assembly. Two separate propellor shafts enclosed within torque tubes veed
rearwards to drive the wheels through simple bevel boxes attached to each hub.
Historical controversy clouds the reasoning behind this system, although claims
of reduced axle ‘hop’ and added ease of final drive ratio changing to suit
varying circuits seem logical. The Monoposto (literally ‘single-seater) made
its debut at Monza in the five-hour Italian Grand Prix, held in June 1932. With
Nuvolari at the wheel, it won. Three more major victories fell to this car
before the season’s end, and then Alfa Romeo bowed to economic strictures for
1933, leaving their racing honour in the hands of Enzo Ferrari’s private
Scuderia with older models, and put the Monoposti into store. When the
re-engined Monza cars proved fragile, the Milan management relented and
released the Tipo Bs to Ferrari. Luigi Fagioli drove the first car to a win at
Pescara, and he and Louis Chiron quickly added four more major victories. In
1934 a new 750-kg maximum weight Formula came into effect, for which the German
industry had built powerful new all-independently-suspended cars which should
have rendered the solid-axled, leaf-sprung Alfas obsolete overnight. An
85-centimetre minimum width rule led to the Monoposto’s cockpits being bulged,
and with 2905cc engines and 255bhp the P3s won no less than thirteen major
events, old 2.6-litre models winning twice, and a streamlined 3.2 model once at
Berlin’s AVUS speedway. For 1935 modified suspensions, 3165cc and later 3822cc
engines were adopted to stave off the German menace, but normally they were only
successful in the absence of Mercedes and Auto Union. Nuvolari’s genius brought
them the Nürburgring triumph to add to their fifteen other successes. Richard
Shuttleworth won his first Donington Grand Prix in his private car in England
and thereafter the Monoposto became one of the earliest, generally acknowledged
‘historic racing cars’.