A good point. Another thing to consider is that the process of opening Oblivion Gates was already known and performable by the Conjurers prior to the Oblivion Crisis, it's just that the gates weren't sustainable and would fail in time. (only seconds to minutes) So the Amulet of Kings and white gold can't be a required part of the process of forging the Gates, but rather they would be relevant to what prevented Oblivion Gates from being sustainable, which is the barrier.
Let the mechanic prepare a chamber, sealed against all daylight and disturbances of the outer air, roofed and walled with white stone and floored with black tiles. All surfaces of this chamber must be ritually purified with a solution of void salts in ether solvent.
A foursquare table shall be placed in the center of the room, with a dish to receive the morpholith. Four censers shall be prepared with incense compounded from gorvix and harrada. On the equinox, the mechanic shall then place the morpolith in the dish and intone the rites of the Book of Law, beginning at dawn and continuing without cease until the sunset of the same day.
The mechanic may then present the purified morpholith to the Daedra Lord for his inscription. Once inscribed with the Daedra Lord's sigil, the morpholith becomes a true sigil stone, a powerful artifact that collects and stores arcane power -- similar in many respects to a charged soul gem, but of a much greater magnitude. And it is this sigil stone that is required to provide the tremendous arcane power necessary to sustain the enchantment that supports the transpontine circumpenetration of the limen.
To open a gate to Oblivion, the mechanic must communicate directly, by spell or enchantment, with the Daedra Lord who inscribed the sigil stone in question. The Daedra Lord and the mechanic jointly invoke the conjurational charter [2], and the mechanic activates the charged sigil stone, which is immediately transported through the liminal barrier to the spot where its sigil was inscribed, thus opening a temporary portal between Mundus and Oblivion. This portal may only remain open for a brief period of time, depending on the strength of the liminal barrier at the chosen spots, several minutes being the longest ever reported, so the usefulness of such a gate is quite limited.
[1] Interested students are invited to consult the works of Albrecht Theophannes Bombidius and Galerion The Mystic for the fundaments of this discipline.
[2] Recommended examples of the conjurational charter may be found in Therion's Book of Most Arcane Covenants or Ralliballah's Eleven Ritual Forms.