Here are hi-res photos of an unassembled Sinclair ZX81 kit, with German assembly instructions.
The ICs and their sockets. 8 KB ROM, two 1Kx4 RAM, the Z80 CPU, and the ULA.
The other components.
The top case and the bottom case.
The power supply and the cables.
Assembly instructions (German). Includes schematics. (1.3 MB)