During such times as any aircraft is held by a licensed dealer for sale, exchange, delivery, test, or demonstration purposes, and solely as stock in trade of the dealer’s business, an aircraft dealer’s certificate may be used in said aircraft in lieu of any registration certificate, or sales, excise or other state tax as required by the laws of this state.

Source: SDC 1939, § 2.0704 as enacted by SL 1966, ch 1, § 9.