Where can i find information on 513 mp detachment unit from the vietnam war?

I can't find any info on it online; however, if you go to this guestbook and scroll down to Nov 9, 2005, you'll find the email address of a veteran who says he was in that unit, perhaps you could contact him for information: a href="http://new75thrra.com/gbook/gbook05.html" rel="nofollow"http://new75thrra.com/gbook/gbook05.html/a