There’s a nice build of the Kasman that was featured here on Armorama. Once you see the “quality” of the window frame casting and the fit of the windows them selves, you’ll see why AEF Designs always gets bashed on this site. Still, the guy did a great job given what he had to work with.
I’m no expert on IDF M113’s but it looks more like the drawing of the Meshupar, of which there is a kit in 1/72 scale. I’ve thought of purchasing it just to scale it up.
Edit: I didn’t read the whole story - yes, apparently the build is of a Kasman Maoz Mashupar, third in the evolving series.