I couldn't find a simple crown model online that I loved so I made my own! It's high resolution enough that you should be able to scale it up or down or keep it at its normal size and not see any artifacts (like the circle having flat sides or anything).

Using the included Fusion 360 file you can also easily modify the crown as you see fit with the given parameters, which include height, thickness, number of points on the crown, angle of each point, etc.

The included print profile is 25 mm in diameter and a cute, smaller prop size, but you can scale it up to something like 140 mm in diameter and get an actual real life crown size! Scale away!