Hi encapuchado,
I, too, work with "Lastname, Firstname" to sort my authors, and I, too, start with Sigil ... so here is what I do ...
1. Open your epub in Sigil. Open the "content.opf" on the left side. Nearly at the top of the file you should find the following line:
Code:
<dc:creator opf:file-as="Name, Name" opf:role="aut">Name Name</dc:creator>
Change this to
Code:
<dc:creator opf:file-as="Lastname, Firstname" opf:role="aut">Lastname, Firstname</dc:creator>
You have to do this as the last step before saving, because there is something inside Sigil at work that will change those around on some logic I do not understand whenever you change anything in Sigil that gets written into the content.opf file ....
This step forces my PRS-650 to show the author as "Lastname, Firstname" on my device (as I want it to do) - and Calibre imports them that way if I import my books (with "read metadata from files")
2. Before importing the books into calibre, open calibre, and in preferences set the author sort to
Code:
author_sort_copy_method = 'copy'
3. Make a new library, and import your books - now you should see "Lastname, Firstname" everywhere
