Czerweny CZ 2000
The CZ 2000 is a ZX Spectrum computer on a TS1500-style black case. Those were assembled on the Timex of Portugal factory for the Argentinian market until Czerweny started to make their own clone, the CZ Spectrum. Sinclair ZX Spectrum Issue 4 and 6 boards were used on those machines.
Czerweny later upgraded the CZ 2000 to the CZ Spectrum with the new casing, same rubber keyboard, PCB was a ZX Spectrum issue 4B clone that looks like an issue 6 board, video composite out, reset switch, and 2 joystick ports.
The new casing was shared between the CZ1000 Plus, the CZ1500 Plus, and CZ Spectrum. Because of the Argentina/UK conflict, Czerweny did not have access to Ferranti ULAs and with permission of Sinclair, Timex of Portugal served as an intermediary to allow Czerweny to have them. Timex also sold other components to Czerweny.
Later Czerweny gave CZ Spectrum a smaller casing with a Spectrum Plus keyboard and named it CZ Spectrum Plus. Looks like a cut-down ZX Spectrum Plus!