How many OSI 1200 Spider and Coupés were built?

Up to now there are no exact production figures of 1200 OSI or Neckar St Trop cars available. The figures vary from 105 cars in total up to 280 Spider and about 70 Coupés. Even the VIN gives no clue because OSI appearently ordered chassis from the Fiat factory always just in time to their own production, so there is no continous series of VINs. But OSI had, as many other low-volume manufacturers, given it's own production number to their cars. This number can be found on various parts of the car, e.g. the inside of the door panels or at chrome parts. But first of all it can be found on the left front wing, next to the battery.

The OSI production number can be found on the backside of the inner door panels, together with a remark on the interiour colour and if it's for a Spider or a Coupé.
Here the panel of the OSI Coupé 00221 and the OSI Spider 00485.

All cars have their internal OSI production number on the left front wing near the battery.
The photo on the right shows the number of the OSI Spider 00081.

The OSI 1200 and Neckar St Trop Spider also have their number on the right side of the folding roof linkage

Here for example the OSI 1200 Spider 00024 and 00162

If you assume that all production numbers were actually used, it is quite likely that OSI built a little more than 700 cars in two years. The lowest number in my registry is the OSI Spider 00024 and the highest is 00733 – also an italian OSI 1200S Spider.
So when "Ruoteclassiche" publishes a total of 280 OSI Spider and some 70 OSI Coupés, it is quite likely that their figures only refer to the Fiat models. It is safe to assume that at least the the same amount of Neckar models were produced in this period.