Is there a way to transfer the layout/CSS data from one epub to another?

I got a copy of the Great Gatsby from Project Gutenberg and when I send this via email to my Kindle the layout looks great.

I’ve got some other epub files that when I transfer to my kindle in the same way via email the layout isn’t as good.

I presume this is because of the layout/CSS settings in the respective epub files.

Is there a way to transfer the CSS/layout data between two epub files?