ASU-57 airborne self-propelled gun (Russian)

This is a 1:76 model of the post-war Russian airborne 57mm SPG. It has proved challenging to print, and is not ideal at present, as the tracks do not print particularly well, and the model is not easy to split into different parts if separate printing is preferred.
The model was based on a skin model found in the SketchUp library (published by Andrei M., to whom my thanks), but required almost complete re-skinning to get round zero-thickness issues. I suspect that the remaining challenges wit