Starfox
Masterpiece
Just get some fiberglass cloth like the use for auto body repair, cut it up and Mix it in with 1 part Portland cement and one part peat moss. Basically the same stuff, but maybe even more reinforced due to being able to control the length of the fibers. And cheaper this way and just like clay
I'm pretty sure I have a few small bags of quick set cement and if it isn't water damaged I might give that a go.