The Fiat 124 (Spider) was the direct replacement for the 1500/1600S "Kabriolet", that Fiat built from 1960 to, I believe, 1966.
The 1500S started out in 1960 with a 78HP 1500cc OSCA engine, two double barrel Weber carbs, disc brakes front and rear. In 1962 it was replaced by the 1600S with the slightly boosted displacement and 90HP, while a 1500 "non-S" version was continued with the SOHC motor out of the 1500 Sedan. These things were screamers. The engine was made by race engine manufacturer OSCA, which was founded by the Maserati brothers and was commonly called a "Maserati" engine. Although the standard tranny was a 4-speed, it was available with an optional 5-speed. Several body manufacturers took turns to put custom bodyshells on the "Kabriolet", especially the 1600S, most of them Coupes. In good condition, they command outrageous prices today, compared to what they were new.
I still keep in touch with several owners in Germany
Apologies for hijacking the thread!