The ISU-203 is a what-if vehicle basd on concept drawings created for mounting a 203mm mortar into a SU-152.
The idea comes from a drawing I found in the WOT book on the development of the SU-152. Apparently 152mm wasn't enough and they wanted to jam a 203mm howitzer into the fighting compartment. Crew comfort and ammo stowage with the 152 was bad enough so yeah, cram something bigger in there. I didn't have a SU-152 kit so I used the closest thing in the stash, a Tamiya ISU-152. I received the kit as a kit. it was partially started so finishing basic assembly was a breeze.
I designed a new barrel in 3D CAD and sent the file to Shapeways to print as a high res SLA. The print was a little rough so I has a bit of sanding to do. I added Master Club white metal tracks, Eduard, ET Model and Voyager PE, and Eureka XXL tow cable. Additional details are scratch built. Grab handles were replaced with brass wire.
The model was painted with Tamiya acrylics and weathered with oils, pigments and enamels.