Using InDesign to make a tête-bêche book

Tête-bêche (fr – head to tail)  this book format is like the old pulp-fiction books and can be read from either side, effectively having two front covers. Online printing services can make it for you. It is possible to use Adobe Acrobat to rotate 180 the pages on the second book, but this won’t translate into useable artwork for services like Blurb. Instead, you have to set it up in InDesign.

I have book one, which I export as a pdf as pages not spreads and with bleeds on Top, Bottom, Outside only.
Book two I also export as a pdf with the same settings. Both books are the same size in my case

Get this InDesign Multipage PF and Indd importer script here.
Add it to InDesign by placing the script in the correct folder there’s a guide here.
The Multipage PF and Indd importer script will pull in your pdf.
First set up a blank doc with a matching page size and bleed to your book one.
You only need to make 1 page.
Under Utilities/Scripts run the script and in the popup dialogue window choose, Reverse page order, Centre, relative to spine and Rotation 180.
Hit ok, sit back and it should all work fine. Now you can export this pdf, with the same settings as before.

Adobe Acrobat Pro DC reader can be used to combine books one & two using the Tools/Combine Files