You're going to have to check the German sites. I forgot where I got my kit. The guy that made the kit also furnished me with photos of the 2 SU-76is at a museum near him. The Sig 33 is also a relatively easy conversion and a little modelling of the Tauchpanzer can make it very realistic with nothing by sheet styrene and basic modelling skills. All Sig 33s were lost at Stalingrad, but it was a neat carrier for the massive 150mm howitzer.