I found the New Tab icon in Customize and dragged it to the Navigation tool bar. I stumbled upon dragging it to the Tab Bar from the Navigation bar while in Customize and poof the Plus sign reappeared to the right of the last tab.

OK. Good. I had the new tab icon in the tool bar. Apparently it can be in the tool bar, the tab bar or in Customize. You choose which one only of the three. In the tab bar it persists all the way to the left of the tabs (for me). It would be nicer on the right, but OK. Thank you.

It is probably on the left because that is where you dropped it. Try dragging it to the right and dropping it.

Hi. Sorry, no. Tried just dragging when Customizing. Even moving it back to the Customize "box" and then up to the tab bar and carefully positioning it to the right of the only tab - it snaps to the left of the bar. Tabs on top or bottom has no effect. I vaguely recall upon the original installation it was on the right. Thank again. M

Go to the customize section by right clicking the toolbar and in that window of drag and drop menu items, there is a box labeled 'Restore Default Set'. That will change your entire toolbar back to firefox default and will also return that convenient little tab - to the right of the last opened tab. Then you have to change everything else back - may want to do a screen shot b4 changing. Hope this helps.

OK! Also the screen shot helped as well. Good idea. Thanks, M