Are the following expenses deductible repairs:

Sid runs a motel business and as a result of rust to the baggage he takes the trailer in for welding and painting, costing $1,500.

Part of a ceiling in a Darwin butcher's shops needs fixing. The owner decides to replace the entire ceiling with different better material to insulate against the tropical heat. It cost $100,000. Repairing would have cost $10,000

Andy purchased a second-hand machine for his business, it cost $44,000, however it had two broken springs which cost $7,000 to repair. Can he claim the $7,000 as maintenance and repairs?

Ensure you refer to applicable legislation and case law and reasons in your answer.