Many of the repro accessories are very difficult to tell from originals. The repro hatbox is slightly smaller than the original, but of course that's not something you can tell without an original to compare it to. Also the red material it's made of is shinier than the original. Basically you just need to assess whether it looks new, because I've never seen an original that doesn't have some signs of wear.
The only surefire way to tell if it's an original is if the Barbie on the front is followed by a TM rather than an R. The earliest examples had the TM, while the later versions and the repro have an R.
