Vintage barbie open toe shoe question

[designforyou]

I sold a pair vintage barbie black ot shoes.  The buyer claims I sold two right shoes and they are not Mattel shoes.  One shoe is marked JAPAN and the other shoe is unmarked.  I asked the buyer to return them for replacement.  I have never encountered this in my 10 years of collecting/selling vintage Barbie.

So my questions for the experts is:

How can I tell if an OT shoe/s is genuine Mattel shoe/s?

Which shoe is marked JAPAN?

How can one ALWAYS tell difference between the right and left shoe?

[sunkist_rio]

Hi...the shoes are not perfectly round at the toe so if you look down at them you can see if they are right or left as they are a little slanted on one side.

The #1 shoes with the hole are marked on the left shoe...the #2 shoes are marked on the right foot and tend to be a little smaller; the #3 shoes are marked on the left foot.

as to how you can be sure it's Mattel I'm not sure how to put it into words but they are the only shoes that looks exactly like they do..they are  a bit more substantial and a bit bigger than the clones and I think the only ones that are marked exactly like they are..

[designforyou]

Thank you!  That certainly helps with identification.