M103A2 Vietnam???

I found this pic on a forum in a foreign language which I think was from Indonesia, but I'm not sure. I could not get it to translate, but I know it was about the M103A2. It sure looks like Vietnam to me due to the red clay earth and the uniforms of the Marines. I also found this .pdf that looks like someone's notes from either writing a book or paper. It says that all USMC tank battalions had a heavy tank company attached during the Vietnam years. However, Oscar Gilbert, whom I met once at AMPS and is a super nice and smart guy claims in all his books that the M103A2 was not deployed to Vietnam with the USMC tank battalions. So I'm trying to find out if that is right or wrong. Why would they leave a company out of a battalion behind before going to combat? Does anyone know if there is like USMC tankers forum somewhere where the question could be asked of veterans? Or have any other ideas on reference resources fro this question?

Thanks.

JG