Correct as above, truck is from 131st ENGR Vt Army National Guard. The "LE" stands for "light equipment" company.
Your truck is not from "just another guard unit." You should be proud to restore it to it's original markings.
This outfit was activated Oct61-Aug62 for the Berlin Crisis. It was activated again from May68-Sep69 for Vietnam. The 131st LE spent one month at Tuy Hoa and then moved to the central highlands near Cambodian border at Ban Me Thout for the remainder of its TDY. It was part of the 577th ENGR BN, 18th ENGR BDE. Over the decades, the 131st has fielded rock crushers, 5T & 10T tractors, all sizes of dump trucks, graders, scrapers, dozers, and many other combat-support vehicles.
The 131st was activated again in Nov90-May91 for defense/liberation of Kuwait and Saudi defense, and again Jul06-Jan08 during the current conflict.
Somewhere in my albums I have pics of M817's from the 131st's CS (combat support) company doing a fill job in the 1980's up at Ethan Allen Firing Range in Jerico (Vt) .. I also have many pics of M817's and 20-tons in the 1970's/80's of their attached 45th ENGR Co. Many of the 817's were still OD w/stars working alongside MERDC-painted 817's in 1976-78. The 131st (and 45th) received newer versions of equipment rather quickly. They started turning in their M39-series for the M809-series in the early-mid 1970's. By the mid-1980's they had turned in their M123's for CHET's. (M911's)
I personally know a few of its Vietnam-era members, one of which was with the unit in Vietnam. My son was also a member for a time.
Campaign Credits:
Vietnam
Counteroffensive, Phase V
Counteroffensive, Phase VI
Tet 69/Counteroffensive Summer-Fall 1969
Southwest Asia
Defense of Saudi Arabia
Liberation and Defense of Kuwait
Cease-Fire
War on Terrorism
Campaigns to be determined