Good job! Looks like you put a lot of work into the details.
A few suggestions, if I may (though I'm just an amateur):
-The frill, as a probable display structure, was quite likely to have been
brightly colored. Perhaps some bright yellow with red patches over where
the "hooks" would be?
-The front legs, well, upright vs. sprawling is an issue that recurs a
lot... Last I heard, though, the latest studies favored sprawling. Maybe a
bowlegged posture with the feet tucked under the body with the rest of the
leg angled outward, as ceratopsian tracks seem to have been made in fairly
narrow paths.
Anyhow, I'm impressed