On the other hand, the one in the video you linked is an S1, which wasn't ever really a thing(one prototype was made), so calling THAT an "S-tank" might be excusable. But the 103, not so much. Incidentally, it never had a name as such, in contrast to the Patton or Leopard. Sweden has never been much for naming gear in that manner, up until quite recently. Tanks have been the "103" or the "81" or the "122" or similar, and other vehicles have been the BV(bandvagn, "tracked vehicle")206 or SF(stridsfordon, "combat vehicle") 90. The CV90 is/was further differenced by the gun carried, such as 30/35/40/120.

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Stoke Mandeville, Esq & The Victorian Ballsmiths
"Nobody Want Verdigris-Covered Balls!"