I suggest you to save the facing pages document and place it into a non facing pages one.
It’s the easy way to achieve your goal without having to manually assign different master pages to ex even and ex odd pages.

Hi Linus,
I have several InDesign versions installed on my Mac, no one of that can apply stroke styles to live text.

Do you remember which version could do this?

You might have applied the settings without any object selected so that InDesign uses those settings for any new object.

Hi Randy, you can open all the documents and use the search and replace to apply the superscript to SM in all documents in a single step.
To have access to the formatting options in search and replace you have to click the more options button.

Hi Glen, this seems to works fine:
(?<=PM )£\d+\.?(\d+)*

(?<=PM ) without square brackets
£\d+\.?(\d+)* this apply the format to the prices

Let try it

You can change the height of the underline to make it thicker, option + click on the underline icon, it’ll open the underline options

Hi Phil, if I where you I’ll try too create two separate master pages, one for the recto and one for the verso pages, so that your pages panel will be an alternate series of the two masters that will never link each other.

If you want to follow the idea you’ve described, I suggest you to create the two separate documents without numbering and, as the final step, create a unique INDD document where you can place the two separate original documents and apply the numbering to the final document. Maybe a custom script can do this final step automatically.