The breakthrough for reproducing the aluminum tailpiece of the '50s happened when we discovered 3 in-process or unprocessed parts among Kalamazoo plant leftover parts.
Just out of the mold, with flashes, and unplated, these pieces gave us enough insight to deduce the work process of the time. Upon examining original tailpieces and in-process parts,
we could tell they had not been uniformly molded to start from, and they had gone through time-consuming hand-grinding process.
This was precisely the reason behind the "individuality of shape and weight", that replica tailpieces could not reproduce thus far.

The manufacturing process used here is "Pressure die casting", the same technique as back then, consisting of injecting pressurized aluminum into the mold.
At this point, it is just a block of aluminum, without any processing of details. The advantage of this block-like shape is to maintain uniform density,
much like Rolex Oyster case is cut out of solid metal.

Once it has set, and while it is still warm, the craftsman removes the aluminum from the runner, hitting it boldly and carefully at the same time with a hammer.
There are many flashes left on it, which means we are reproducing the rough mold casting of the time. In fact, these flashes are going to be the key to the subtle shades and reliefs after they have been removed by hand-grinding. Yet another characteristic of THP tailpiece is that string holes are drilled one by one afterwards, to reproduce original density, while they could be processed in the mold as well, in modern casting technology.

Then, the grinder mark behind the anchor hole (unique to vintage), the inner edge, and the delicately sloped surface are shaped. See how these warm and full distortions and strains on the surface, so reminiscent of the old times, make for a nuance perfectly matching Les Paul top.

In the plating process, too, the Tailpiece 59 is given a special twist to be a true replica of vintage. In those days, aluminum die cast products such as Bigsby and strap pins were mainly finished with a shiny surface. Thick nickel or gold plating was rarely done without brass undercoat. In addition, since oxidation, insufficient cleaning and pretreatment can lead to plate peeling, careful preparation is crucial.

The huge amount of work that Gibson put into manufacturing only 3000 pieces must have made it difficult to replicate the tailpiece.
The 3D scanning device, the 5 human senses, and Ace Iwasaki's determination and passion brought back to today the touch, look, and sound that had never been materialized before.