I'm no expert in the War in Vietnam or US Military History, but I'll do my best.

It appears that the second inscription is "588th Sig Co (SPT)" which indicates that the person (your grandfather) was a member of that unit. The 588th Signal Company (Support) was under the 63rd Signal Battalion (which has been inactivated and reactivated a number of times and is now the 63rd Expeditionary Signal Battalion) of the Signal Corps. The 588th Signal Company arrived in Vietnam on 3 May 1967 where they became part of the 39th Signal Battalion (Support), 2d Signal Group and were deployed initially to Bearcat Base which was located in Biên Hòa in Đồng Nai Province in the south of Vietnam.^1 The came from Fort Irwin, California and managed to forget a truck in California when deploying. Within the first few months of being in Vietnam they went through numerous reorganizations in which platoons where swapped with other Companies or battalions to keep sizes and duties apportioned fairly.^2 On 8October 1968 the 2d Signal Group received a Meritorious Unit Commendation for their supporting efforts during the period of 1 July 1966 to 30 September 1967, which coincides directly with the engraving on the lighter.^4

As for the "LOST PLATOON" inscription: this would indicate some knowledge or involvement with the Battle of Ia Drang, 14 November 1965, in which a Platoon became separated from its Battalion and encountered a North Vietnamese Army battalion and was completely overwhelmed and the remaining soldiers (some seven?) were forced to play dead and wait for the rest of their Battalion to arrive and save them. This occurred after days of fighting in which some 230+ US and 1800+ Vietnamese soldiers were killed.^5 The dates, however, do not appear to align and so I would be suspicious if this was the case, though there are circumstances in which this might be possible. It appears that there were numerous cases in which so-called "lost platoons" had to play dead and hope for salvation from other units (see Chicago Tribune and San Antonio Express).^3 It could be the case that this was merely an internal designation that the members of your grandfather's platoon gave themselves as this is a fairly common phrase used in many different cases to describe thoughts towards their own battles. It could also be the case that your grandfather had family or friends that fought in that battle and he was merely keeping that memory close to him.

Sources:

• 1. AD827118 - Operation Reports - Lessons Learned

• 2. AD386715 - Operation Reports - Lessons Learned

• 3. Chicago Tribune - Lost Platoon GIs Play Dead

• 4. HeadQuarters - Department of the Army - Section II

• 5. San Antonio Express - 'Lost Platoon'