Trincomalee, Unicorn, and differences within a sailing-ship class

Was Unicorn modified to give it a rounded stern?

The rounded shape is described as normal for many ships of its period, rather than a special modification to Unicorn.

Trincomalee's teak construction provides a point of comparison with Unicorn. Ships belonging to the same class can nevertheless look different inside after changes to their construction and arrangement. Unicorn's rounded stern prompts a question about whether it was a later modification. That shape was common among ships of the period, so its presence does not establish a special alteration to Unicorn.