The Multiplex car you've posted there uses an Allied Fiberglass body, itself a copy of the Cisitalia 202.
Here's some info:
"Mickey Thompson, along with his hot-rodding buddy, Bill Burke, decided to borrow HOT ROD and MOTORTREND magazine publisher, Robert Peterson's, new Cistalia 202 coupe. Apparently unbeknownst to Peterson, they took a plaster mold from the Cisitalia coupe at the shop of customiser George Barris while the Cisitalia was awaiting a new paint job. In the Summer of 1952, the two then enlisted the help of experienced 'glass man Roy Kinch to help with the making of permanent molds and the lay-up of the production bodies. The name of the new venture was called the "Atlas Fiber-glas Company", but was soon changed to "Allied Fiberglass" after the the former name came into conflict with another fiberglass producer.
The first bodies produced were dimensionally exact to the Cisitalia and were thus installed on small car chassis's like MG and Triumph.
A while later, a larger body was produced that could fit over domestic chassis's with 56"-60 track and 98-102" wheelbase. A few of these larger bodies were mounted onto Kurtis 500KK kit car chassis. These aforementioned cars are the most sought after Allied bodied cars.
Bill Burke built an Allied coupe with a tube chassis and Ardun-Merc engine and held the sportscar class at Bonneville for many years.
It is rumored that Mickey Thompson built a Allied coupe to race in the 1955 La Carrera Panamericana road race in Mexico, but never ran it due to the race being cancelled.
The exact amount of bodies and completed cars that Allied produced is unknown, but many have guessed at around 50 total.
Allied supplied finished bodies to Mulitplex Mfg in Pennsylvania (a builder of railroad cars) who built three finished cars between 1952-54."
