The 75th Airline Anniversary committee spokeswoman, Heleen Johnston, says a wooden aerodrome building of unknown vintage had just received its final lick of bright orange and grey paint.
"It is absolutely horrible but those were the colours.
"It's been on the site since the year dot," Mrs Johnston said.
The historic Haast Aerodrome Terminal is either the original terminal or an early replacement of the terminal and is between 50 and 75 years old.
More information on the building would be welcome, Mrs Johnston said.
The rose in front was planted by the late Alvilda Cron many years ago.
Meanwhile, work was continuing at pace yesterday to erect an 18m by 53m marquee for a roof-warming shout and the anniversary dinner on Saturday night.
There will be 22 stalls and displays at the airstrip on Saturday, including 10 food stalls.
Joyrides will be available in three vintage aircraft - a Dominie, Fox Moth and a Dragonfly - with prices between $100 and $150.
A book launch by aviation writer Richard Waugh will go ahead even though Mr Waugh is in hospital with a burst appendix.
His book is titled Hoki to Haast - New Zealand's First Airline.
In addition to the airline anniversary, artist Liz Hawker and photographer Gilbert Van Reenen are hosting an exhibition at the Heartland World Heritage Haast Hotel on Saturday afternoon entitled "Stranded".
The photographs, and prints on canvas and paper, tell the story of sealer gang castaways who lived on the Open Bay Islands between 1810 and 1814 before they were rescued.
