The Qantas Founders Museum is an entity independent of Qantas, managed by it's own Board and supported by Qantas and other airlines and individuals.
Put where at Longreach??
There is already a B742, B707, PBY Catalina and DC3 at Longreach airport exposed to the weather and costing money to maintain. I understand a Lockheed Constellation may also be headed to Longreach in the future.
Where do you propose another 747 should be parked and who will pay the construction costs and continuing maintenance costs?
Indeed, can a 744 land at Longreach?
It may be an urban myth, but I understand parking the 742 at Longreach was the most cost effective solution for Qantas. Rumour has it they did not want the aircraft scrapped in Australia and parking at Longreach was far cheaper than flying it to the USA and parking in the desert.