I bought my TurboGrafx-16 in September or October of 1990 at Babbage's. I just started high school that year, it was a really busy few months for me, that's why I don't remember if it was Sept or Oct.
I definitely had that poster.
But what I'm most interested in, is the mail-in offer for free TG16 game of choice, including R-Type. Does anyone have a picture of it? I found a picture for NEC Home Electronics business mail for my Christmas Eve 1990 thread, but I'm not sure if that was an actual free game mail-in offer, and I'd like to see both sides of one if anyone has it.