] I see that in the lower case letters there are both a "u" and a "v" -- but not so in the upper case letter. The Round Hand and the Flourishing Hand both appear to have a "U" but not a "V" while the Italian Hand has only the "V".

This came up at Christmas when I posted a Regency Rhyme, for which the answer was clearly Alphabet, yet the clue read:

A Word of three syllables, seek 'till you find
That has in it the twenty-four letters combin'd.

I was confused about the twenty-four letters part, but Emilie made all clear. It is as you surmise - J and U were known, but in writing were indistinguishable from I and V.

Regency dictionaries are confusing because they mix the J/I words and the U/V words together. I always forget, and it takes me ages to find what I want.

Here a link to the Twenty-four Letter Alphabet thread.