27 CFR 53.176 - Supporting evidence required in case of price readjustments.
No credit or refund of an overpayment arising by reason of a price readjustment described in § 53.174 or § 53.175 shall be allowed unless the manufacturer who paid the tax submits a statement, supported by sufficient available evidence:
(c) Showing the price at which the article was sold, the amount of tax paid in respect of the article, and the date on which the tax was paid,
Title 27 published on 2014-04-01
no entries appear in the Federal Register after this date.