Calculators: Sinclair
British calculator manufacturer famous for innovation at a cheap price.  Most of these calculators were also available in kit form in the UK.
The Oxford series comes in two (maybe three) distinct types: Type 1 has (usually) red LED displays, thick plastic case bars either side of the display and a flat upper section whilst Type 2 has green VFD display, thin bars and a top section that sloped back.

Hybrid models