Is anyone aware of a ruling or case that addresses the situation where a valuation for purposes of a gift for estate planning purposes is not consistent with an ESOP valuation. I recall that there was some guidance on this issue, but can't seem to find it. It seems to me that this should not be a problem as they are very different animals.

Appreciate any guidance.

Why do you think that they are "different animals"? If you have different valuations, the IRS can use one valuation to challenge the other. The IRS could use a gift tax valuation to show that the ESOP overpaid for its stock, or it could use an ESOP valuation to claim that the stock was undervalued for gift tax purposes (which can get really messy if there is a GST issue).