You can use this add-on and put some of those add-ons back:

https://addons.mozilla.org/en-US/firefox/addon/status-4-evar/

Perhaps I didn't make myself clear enough. The reason I was looking in the add-on bar for a shortcut or icon to start my add-ons is that I simply couldn't find any way of starting FireFTP and various others in Firefox 4 (I've just now found it in a sub-menu under Web Developer in the main Firefox menu!). My add-on bar *does*in fact contain an icon for one of my add-ons, WebMail Notifier, but that's all out of about 8. One or two have appeared in other ways. The link you supplied seems to be to an add-on that reinstates the status bar but it's not the status bar I'm missing - I want somewhere from which I can readily access all my add-ons, which was previously easier. Possibly some of the fault lies with the developers of either FireFTP or Web Developer - I don't understand why FireFTP has been hidden away within Web Developer.

In 4.0 the Add-on bar is like any other Toolbar. Unlike the old Statusbar where icons / buttons automatically appeared, the new Add-0n bar needs the user to place the buttons / icons exactly where the user want them to be using the Customize mode. Some extensions may still use the old coding for Statusbar buttons, so those extensions may have icons / buttons that still appear automatically upon installation of those extensions in the area of the Add-on bar reserved for "statusbar icons" for backwards compatibility.

https://support.mozilla.com/en-US/kb/How+to+customize+the+toolbar
http://kb.mozillazine.org/Toolbar_customization

As far as the FireFTP menu item being hidden in Web Developer, that was done by the developer of FireFTP for reasons only he knows, he probably thought that was the most appropriate location for that menu item.