Fortunately, milliput responds really well to being reshaped when wet, so those horribly jagged edges might yet be salvageable without having to file bits off. I think what I'll do is switch to procreate for the surface detail: saddle shaping, buckles on the strap, nostril things in the swan beak. Oh, and that nobbly bit that mute swans have above their beak:
I'll have one more go at sorting the joints with milliput, just to get some practice.
Hopefully your sculpting is proving more successful,