Curious---Tad left or right handed?

[Eva Elisabeth]

It doesn't look to me as if written by one person - to me it looks as if all the three items (the "Thomas Lincoln" you posted and the "TL" and the "T. Lincoln" in the book I posted) were written by three different people, of which the "TL" writer was likely someone whose hand wasn't much trained in writing (like first/second grade elementary student). The "T"s especially look all totally different (as do the other letters).
   
I think Tad possibly wrote the initials" TL", and if so - the other handwritings look way more skilled.