Federal estate tax deduction for NYS estate tax

Taxpayer has an estate that is below the federal threshold, but not the NYS threshold. Thus, the estate pays NYS estate tax of $350,000. I believe that the estate is entitled to a deduction on it's Form 1041 estate income tax return for a portion of the NYS estate tax. I have not been able to find anything authoritative concerning this deduction, nor an example of how to compute the deduction to be taken on form 1041. Can anyone assist? Thank you very much.

State estate tax is not deductible on the 1041.

Well, the estate attorney handling this situation told me it is, and that I should do the research. He seemed pretty sure, and he is quite knowledgeable...

Section 164. Estate tax is not listed.
Section 275 says estate tax is not deductible.