Alpha-numeric Character Study of the Ransom Note
The top bends over sharply to the right. No tail at bottom. On some of these note that the stem doesn't end at the bottom on the down stroke but ends as the pen turns back up leaving a "hook" at the bottom of the stem.
Oliva's capital F
The top is curved over. No tail.
On these the "upstroke" from the bottom of the stem is very apparent
The top is bent sharply as in the first row and a tail is added to the bottom.
The first capital "F"
Same as type 1 on the first page
Same as type 2 on the first page
Same as type 1 on first page. My guess is that, since this form is by far the most prevalent and is exclusively the type used on the last page, this is the true style of the RN author.
Oliva's capital F. The above could be made very simply by continuing the crossmember across the stem.