Need some help writing this in Japanese

How do I write the following sentence in Japanese.

"May I know what are the missing (something) in the item?"

何が足りないか教えていただけますか？

May I know 〜? 教えていただけますか？"

What is the context/situation?

Are you trying to buy an item/product from an online auction or something, and the seller says it's not a full set?

@AK

Yes. I understand a bit of Japanese and I assume 欠頁 means missing page...

Then you might want to be more specific and say:
- When you say 欠頁, could you tell me which pages are missing?

欠頁とありますが、どのページがないのか教えて頂けますか？

Thanks for the help, AK.

I just noticed something... Is "欠頁" and "落丁" means missing page?

I was going to ask, actually (and I am Japanese). I have always known that word, 落丁, and it means "missing pages," but didn't know the word 欠頁 until I read your post :)

But the item you are looking at is a book, magazine, or some kind of paper publication, right? Or it might be an originally paper publication, that has been turned into e-book or something?

Sorry for the late reply.

It is an original publication of a specimen book back in the 1860s. Not a reproduction.

I cannot find any definitive answer on it, but I've seen the word 欠頁 referring to missing pages in art books/digital publications (when the original was missing some pages so they could not reproduce the book in full).