Howdy.. I have that particular insignia in my collection from back with I was in the Texas Army National Guard (almost 35 years ago) but I can't recall which unit it was. There is a picture of it (used as a t-shirt design) on a website at:
http://www.pennantshop.com/us_milita..._-_t-shirt.htm
Maybe somebody can look at this picture and tell us BOTH what unit it is.
I have sent a quiery to some old friends where in with me, maybe one of them can remember. I'll let you know what I find out.
FR Brown
Rowlett Texas