Stuart-Pak is Yugoslav field modification of the British Stuart V (M3A3) which turned it into a tank destroyer, specifically through installation of 7.5cm PaK 40 anti-tank gun. There was also a SPAAG modification. Any good information?
It is a similar idea: cheap way of putting a big anti-tank gun onto a light tank chassis. That is how I actually first came across it: Husar, No.1, 2004., pg.52 - it was a modelling project by Lothar Limprecht, and Husar wrote a short photo article about it. Nice article with some information, but it made me curious.