I have tried the instructions to 'restore all', and so far the important one (AB) hasn't reappeared. However I am hopeful it will once I have visited it a few more times.
I can see you don't use Chrome, Chris, it's more complicated than that.
There is a start up page (probably what you know as a homepage)
However if you click the picture of a house you go to the Google Homepage which is the search page with eight thumbnails of your most regularly used sites..
You could have AB as a bookmark on your bookmark toolbar.
I use Chrome and the home page is the one that opens when you click the house.
The startup page is the one that opens when you first launch Chrome. My startup page opens 6 tabs, including GMail and AnswerBank.
"However if you click the picture of a house you go to the Google Homepage which is the search page with eight thumbnails of your most regularly used sites.."
It doesn't have to be. If you go to settings, down where it says "Show the home button", you can also set what page the Home button will default to.
Either the "new tab page" or a URL or your choice.