I think that this item may be a replacement for Maxi Ball Join, fitting Sierra uprigths with no modification.

The cone seems to be the same as the original track control.

Well wish I had known about this when I was building. I looked every where and could not find any. Good on you.

Mark

That part looks to be designed for a McPherson suspension, and therefore won't have been designed to take any pull out or push in loading.