btw, the covers seemed to be the same on the ones i tested although i don't much care about that. when you get so many loose ebooks from various sources it's very time-consuming to hunt down the exact cover that matches your version and if i can get a cover with the right title, that's good enough for me in nearly all cases.
btw, found this link along the way where the calibre author tells what the embed function does:
https://www.mobileread.com/forums/sh...d.php?t=241809
/guy