Personally, the last time I sold with an adult box, I just used a bankers box that had "ADULT CONTENT 18+" written all over it and it was fine. I don't think anyone checked the dimensions of my box, I think the sizing is mainly a guideline for the amount they want to limit you selling at swap meet, but that's just my theory esp cause the dimensions they list are a bit odd.
I've updated the pinned post on the Facebook Event Page and the second post in the gathering thread on the Fanime Forums with the map to where the gathering will be this year - Location G6. Be sure to check it out!
Back to old school OP's - and I'll tell you, my collection of YouTube hosted OPs has been obliterated compared to years previous. But there's still a lot out there, including this one - a title that I remember being crazy popular in some circles, although it doesn't seem to be talked about much anymore.