This is one of the machines I said was really uncommon and collectable, if only for the reason that Amstrad didn't sell them in the UK. The PC20 is a white version of the "Sinclair" PC200, in other words its the same machine but in Amstrad colours and not Sinclair black.
Of course, the PC200 is as much a Sinclair machine as the Spectrum +2 and +3, but for some reason it's become very collectable despite the fact it's a poorly specced IBM-PC clone with an 8086 CPU and 512k of memory. The PC20 suffers the same bad planning, with 2 ISA slots that would be fully functional as long as you didn't mind having the flap open and the cards sticking out! Most odd.
It does, however, run DOS 3.3 and GEM desktop like a lot of machines of the day, and it *is* quite cute in a sort of 'I look like an Amiga and an Acorn 3010' way. :) Note the rather odd Sinclair software warranty card......click on them thumbnails.