Sorry about the lack of a better description. It appears to be plastic and there are two bosses with a metal insert to mount it to the inner fairing. The ebay item # is 280123309171 - It is not a very good picture but you can see it on the right inner side. I can take a better pic but don't know how to post it - kind of a newbie. Thanks again, Jim
If it's what I think it is, which is what most of these HD fairings use for mounting points, you can take the little round metal threaded part and grab it with some pliers. Heat it with a lighter for a few seconds to get it hot. Push it back into it's round receiving hole in the fairing and hold it for a few seconds while blowing on it to cool it off. It should stay put that way.
Which tab is broken? Is any of it remaining or completely gone? How are you planning to mount it to your X? Are you using an inner fairing?
You can easily repair these fairings because they are ABS plastic. I made modification using PLASTIC WELD (get it at walmart) a soldering iron and some Black ABS plastic I had laying around. The soldering iron melts the abs and permanent repairs are easy.
Use the plastic weld with some fiberglass webbing and that too is a permanent repair.
Here's what I did with Plastic Weld, a Soldering Iron and ABS Plastic.
Cannot tell from the pics, but it looks like the tab on the right, middle way up. If so, the same was broken on mine, so I made a bracket across the top and used the same holes as the windshield. This puts most of the stress at a level even with the handlebars and made it easier to mount. I did not use the inner fairing.
This is a lousy picture but look even with the windshield and you can see the braket and where it mounts to the handlebars. I have a small toolbag I hang there with my wallet, glasses and so on. it works out perfect and I have to long distance roadtrips already without a single issue.