Mrs Hughes discovers the benefits of modern technology on Downton Abbey when she treats herself to a state of the art Art Deco style english made Toaster. It took a bit of searching to identify the make of the toaster.
If you are searching for a similar style early electric toaster you will find plenty of examples on eBay.com but if you want an identical one it may be more of a challenge. The same make as Mrs Hughes toaster is more likely to show up on eBay.co.uk because it was made in England. This is a 240/220 volt toaster by General Electric Co Ltd ( GEC) that was sold in the UK.
Image source: http://www.modip.ac.uk/artefact/aibdc-02405
Above is a picture of a 1930's toaster like the one on Downton Abbey.
Chrome plated metal, black bakelite, black porcelain
General Electric Co. Ltd Made in England - porcelain feet and bakelite handles.
Here is a working model showing how it looks when the element is heated. Mrs Hughes toaster is smoking in the screen capture below but this may have just been an effect added by the prop department.