In 1953, the Wire contacted the owner, Mr Magpie, making him sell television sets cheaply as part of her plan to "tak[e] people's faces, their essences" and get a physical body. (TV: The Idiot's Lantern)
Although Magpie himself was killed by the Wire, Magpie Electricals survived the loss of its proprietor, and continued to exist well past the 1950s.
The monitor, the typewriter, the keyboard and a miscellaneous control by the mustard dispenser in the reconstructed TARDIS console room had Magpie Electricals brands on them. (TV: The Eleventh Hour) A power control device in the console room had Magpie's Electricals brand and was labelled Type V 310 A. (TV: Vincent and the Doctor)
The use of the Magpie Electricals logo is something of an inside joke for Doctor Who's design team. It is on the back of the monitor on the Eleventh Doctor's TARDIS. (DOC: Call Me the Doctor) It was also mentioned on the TARDIS tour on the Doctor Who BBC website.