Here at the images referred to above for an 'old' version of FF Privacy in a 24.0 install.

Not really, seeing "Use custom settings for history" only means that changes were made and some history settings no longer have the default setting.

If you see "(Never) Remember History" then that means that all history and cookie settings are set to the default value.
The "Use custom settings for history" choice allows to see the current history and cookie settings, but selecting this doesn't make any changes to history and cookie settings.
Firefox shows the "Use custom settings for history" selection as an indication that at least one of the history and cookie settings is not the default to make you aware that changes were made.
If all History settings are default then the custom settings are hidden and you see "Firefox will: (Never) Remember History".
"Never Remember History" means that Private Browsing is active and "Always use private browsing mode" gets a check mark.

Ah - thanks. It looked so different, I didn't think of checking the options of changing the History : Firefox will: <option>. Sorry about that. Was in a bit of a hurry from other local activities, and was doing it remotely.

thanks for you feedback - problem solved.

You're welcome.

It looks that in your case it is the third-party cookies setting (never).
Note that current Firefox versions also have a "From visited" third-party cookie setting that may be useful in some cases (embedded media content).