I raided my bits box for all of the parts for this model, except for the World Eaters doors and front plate. I managed to cobble together a complete rhino hull (found parts for another 4!) and a plastic predator turret.
I found the mantlet and ammo hopper from a Blood Angels baal predator as well. The twin-linked lascannon is made from two single weapons I had lying around, although I can't remember what they came from, plus a couple of chaos muzzle breaks. I added the heavy stubber rangefinder weapon so that the ammo visible in the hopper made sense but it has no in-game function. A random cupola and a Khorne icon finished the parts for the turret.
I added a Leman Russ dozer blade as I think it looks way better than the spiky space marine ones. I made the 'chaosy' edging using plastic card cut into strips. I especially like that it makes the dozer blade look like it has teeth.