This article courtesy of the very informative Super Deluxe Edition page:

The full story behind how the mysterious white label, 12-inch 45 release featuring two remixes of Paul McCartney’s Band on the Run album track ‘Nineteen Hundred and Eighty-Five’ came about in the lead-up to Record Store Day, and who was responsible for it, has been revealed…

As reported in a detailed interview with Billboard magazine, it turns out that German DJ/remixer Timo Maas and Canadian producer James Teej were responsible for the release, with Maas having done some work on the McCartney multi-tracks as far back as 2009. The German wasn’t really satisfied with his work at that time: “we never fully succeeded in working the parts to a point where I really felt the end result was worth passing along,” he told Billboard, and so the music lay dormant on his computer until last year, when James Teej came to visit and heard it.

Enthused, the pair then set back to work on creating the two remixes. They were sent to Paul McCartney who gave them his seal of approval.

“We secretly sneaked it [only 300 copies were made apparently] into two vinyl stores in the UK and Germany in order to test the waters and understand how people would react to the music on face value. The response was a little hard to believe,” says Maas, adding, “Phonica’s London store’s phone was ringing off the hook like crazy for copies, and it went to No. 1 on their charts overnight. All of that got picked up first by i-D magazine, and made it all the way to the UK tabloids who speculated that Kanye West might be behind it.”

It’s interesting to learn how this release came about; especially to note the fact that it wasn’t McCartney’s MPL company which put out the white label, rather Maas and his management.

And that now copies are selling on eBay for around the US$200-300 mark….

There was also a limited edition 7″ (a radio edit version) issue on Record Store Day in a run of 100 copies, also through the Phonica store.