"How could all that have been manufactured and assembled in the arid Sinai wilderness?"
It's interesting that Israel still claims "ownership" of the Biblical site of Sinai and its mount, when the Bible account of the exodus (which they admit as being the only account) clearly stated that Sinai was in Arabia. (Exodus 3:1,12; Galatians 4:24,25) https://en.wikipedia.org/wiki/Midian