Despite being purchased for £1 in 2020, the project hasn't been cheap according to the airport's chief executive Suzannah Harvey.
"The company has had to spend nearly £500,000 getting her prepped and ready here, but I think it's money well spent and it preserves her for future generations," she said.
From the outside, little seems to have changed, while the inside has been transformed, stripping away the economy seating to create an events space, turning the gallery into a bar and fitting custom lighting.
Before this, it took a man a week and a half to give it a thorough clean, inside and out.
"It's been a long old slog," said Harvey. "She came into us in October 2020, and at the time I rather naively thought we'd have her up and running by the following Easter.
"We've had such tremendous support from everybody. All the contractors, all the people that have volunteered who are current BA 747 engineers - and here we are finally. She's ready and she's good to go."
The Negus had been part of the BA fleet since February 15, 19944 and operated 13,398 flights tracking 60 million miles.
Its final passenger flight was on April 6, 2020, from Miami to Heathrow while its next life as a party plane will begin on February 12 with a launch party.
A part on board will now cost more than £1,000 (NZ$2040) per hour but the high price doesn't seem to have hampered interest. Harvey said they had been overwhelmed with enquiries.
As the only bespoke events 747 in the world, it's no surprise clients like Netflix have shown interest in booking it out.
Capacity will initially be 120 people, with the chance for it to increase after the launch event.
Those without such cash to burn will soon be able to take a peek inside via tours through a new app.
