Here is something you can try to be able to show Download books.
Step 1 Go to the Settings in the MYBookTable -
- go to Style - make sure the buy now shadow box is clicked Nowhere then save
Step 2 Go to edit book - scroll down to the buy now buttons.
Use the universal buy button (the last on the dropdown list) On the Button text type Download and for the button url give the website link address to the pdf download for that book. Don't use any other buy buttons.
Then click update or publish book.
If you've done everything correctly your book page will have only a download button. The download button should link to a pdf.
To make the pdf link just grab your url for the pdf and put it in the button url box.