You've tested my memory severely; I built that house in 1993, if memory serves, and have done quite a bit since and never expected anyone to put it under a microscope--not even figuratively.
The way a flat surface was achieved was by stripping the top layer of grass off the clay and smoothing the clay surface beneath, wetting it and allowing it to dry as part of that process. Then the goop-like plastic steel was pressed into it and pressed smooth. When it hardened, it was lifted off the clay. The walls were made the same way. Always the side against the clay is used as the exterior side, the other side showing more visible marks of having been hand- and tool-worked.
The house was built first by making the five lower walls (one wall is split to provide access beneath) and driving them into the ground several inches, then applying more plastic steel to the corners to cement them together. The floor was made about two inches larger in each dimension so that it would overhang the walls by about an inch, rested atop the walls, and then similarly cemented to these. The upper walls required more patience, because they had to stand freely on the floor aligned with the walls beneath, but the use of plumb bobs for leveling and plastic steel along the bottom edge got them in place easily enough, and they, too, were cemented together, both inside and out to fill the cracks. The roof was a repeat of the floor; a ladder had been built to reach the roof.
Thus you will see the texture of the clay in your microscope, and probably bits of it that have remained stuck to the surface all these years.
When fresh, plastic steel is softer and more malleable than Play-Dough, but tends toward rougher edges. When hardened, it will do most things that steel will do, and can be used for wire, plating, and solid objects. Most of the machines in Umak Tek are made from it, including looms, stills, spinning wheel, rope twisters, the water tower, piping, stills, the pottery oven, and the frames for the paper making equipment. The only other materials in use here seem to be a white thin flexible plastic (used in sheets), a burlap-like cloth, a paper similar to paper bags, a silky woven cloth, two kinds of thread and two kinds of rope.
In addition to the machines, it appears that someone used this material to make gymnastic equipment, a bowling alley, and a pool table with equipment.
It is also said that the Architect used it to make a rickshaw and a kau sin ke.
--M. J. Young