(valuation of decedent's 15 percent interest in LLC at issue; estate valued interest at $34,936,000 and, on audit, IRS valued interest at $49,500,000; court determined that proper value was less than what estate valued interest at - $32,601,640; estate entitled to refund of $861,422; in revised opinion; court recalculated LLC units used the correct present value factor to value the present value of a reversion to be received at the end of the fifth year and adjusted the value of the LLC units upward by $3,160,120).