This page backs up your units TDY operations to Takhli in 1972:
Your DD214 will or should show you were stationed at Holloman during that period increasing the likelihood that you were deployed to takhli in 1972.
Did you receive any performance reports during or concerning your TDY tour at takhli?
Did you ever go to the infirmary or log any medical visits to the hospital, doctor, dental etc during your tour at takhli? Shot Records? Photographs?
Obtain ALL of your military records from:
National Personnel Records Center
1 Archives Drive
St. Louis, Missouri 63138
Once you receive your record package go through them with a fine toothed comb looking for anything that might indicate you were there.
Check your pay records also. Just flying over the war zone places you in tax exempt status. Check old tax returns filed during that period for any tax exempt status.
Check with family, friends, loved ones for any letters from you that would bear the registered APO for south east Asia and/or any verbiage/conversation concerning your stay at takhli.
These are just some of the areas you might check. Others will chime in with other ways you might be able to prove you were there.