The variables were set upon creating the books in the locations you found them. Do you have 6 books in total? There also exists a book "SUFBOOKA" that doesn't seem to be created via script, did she have it already? EDIT: Yes, you wrote it above. So, I guess Nashkell Carnival is the best available area to try it.
Areas with the appropriate script blocks are: AR1900 (BanditCamp), AR1803 (CloakwoodMines_L4), AR2400 (Peldvale), AR2600 (Candlekeep, Prologue), AR4002 (Gullykin_JenkalsHouse_Cellar), AR4900 (NashkelCarnival). Of course, for Tutu it's not "ARXXXX" but "FWXXXX" in case you want to cheat your party there.
If you first enter one of the areas with all 6 books, there is a timer of 30 seconds before they are combined, so don't be unpatient. Hope it will work now!
You mean, go to the areas with Finch in the party, where I found the books ? I dont remember where I found them anymore. I reloaded a save game that I didnt set the variable. On SK, I have those variables: SUFINCHQBOOK1 to SUFINCHQBOOK4 and SUFINCHQBOOKB set to 1. Dont have the variable SUFinchLibraryItem.
The triggering happens inside an area (triggered by the areascript). I guess it's the areas the books where to be found in. It's a known problem that she doesn't recognize the books if she wasn't in the party (or something like that). By setting the variable you actually deactivated the script block that would make her recognize the books. You could try setting "SUFinchLibraryItem" back to zero and go into one of the book-areas, or you create the needed book by cheating the item "SUFBOOK5".