Graeme, regarding your inquiry about 43rd street.....
43rd Avenue, in reality in New York City, is 43rd street. It has no significance that I know of, as far as automobiles are concerned. 43rd st. is just a narrow one way street, one block over from a very busy two way street, 42nd street, which has theaters and restaurants,and tourists. Back before it was cleaned up and rejuvenated, it was a tourist trap of pickpockets, x rated theaters,and the like.
Me and my cousin used to go into New York for the weekend, back in the late 1950's and besides hitting the Jazz clubs around 52nd st., the Colony Record shop (huge selection), Gordon's Automobile book (and model car) emporium, and every car dealership in the city, to collect auto sales brochures. Nearly all of the showrooms were on Broadway, starting at Columbus Circle at 59th st. and ending somewhere around 49th st. (not sure). There were both Foreign and American, plus Rolls Royce & Bentley on 57th st (later Jaguar), and Hoffman Motors, the first VW dealer, on Park Ave. Don Allen Chevrolet, had a whole block just below 59th.
Fergus Motors sold all kinds of foreign brands. New York was always a great place to spend time. Every make and model car was sold in the city, but not on 43rd street, although the name sounds good, and is connected to New York.