first of all, i want to applaud you for this project, which i'm really in admiration of. i've taken a look at your sample file and for the most part it looks quite good to me. excellent choice to put Bosch's Garden of Earthly Delights on the cover.
i also do appreciate the cross-linking between versions, and the gallery of images at the beginning is very nice.
a couple of remarks :
- is it possible to reduce the greyed-out portion of the cover, to see more of the illustration ? i think it is worth it.
also, take care with black text on a grey background, it might not be the most legible choice. maybe use a lighter grey, or use a black background and white text instead.
- i'm not sure whether this is your choice or mobipocket, but i think a serif font is much nicer for reading longer texts, and particularly here the sans serif seems out of place to me.
- i'm curious also about the thumbnail images in the body of the text ; why not include the full-size versions ? they are so stunning it's a shame not to be able to appreciate them unless you click on the link. and while i'm reading, i don't like to have to navigate back and forth very much, i'd rather have the illustrations linearly in the text. this shouldn't make any difference in the weight of the file, is there another reason you made this choice ?
anyway i'm really looking forward to seeing how this goes ! thanks for this.