Anyway, good luck with this project. It's a massive undertaking but would be well-worth it in the end. I'm sorry I can't help - I live in Australia and was born in the late 80's so I don't remember any Star Wars ads (they probably would've been the US ones anyway - nothing unique).
EDIT:
Looks like I was kind of right. The thread titled "Shadows of the Empire Trailer" turned up a copy of the Vector Prime trailer. The YSI link is there still but long out of date. I remember downloading it but I can't find it at the moment. You can ask daveytod for it, as it was him who provided it via yousendit.
Btw, I remembered I once archived the Force Commander mini-website. Here is the "teaser video" from the site (surprisingly it's still online!): Force Commander Teaser Video.