This is the gear I have.

I have read your submission and as a Licensed Tradesman NSW, I am required to take action,
( I could have ignored your advice request, however)

I am requesting you to barricade the top and bottom of the steps stop using them IMMEDIATELY, also barricade under the steps to prevent any access under and.,

And

Organize for a professional safety inspection, TOMORROW.

SAFETY

The problem is that there could be other places rusted, and severe structural problems,

I don.t want to alarm you unnecessarily,y advice may be over the top, and not required however when it comes to safety, there are no second chances

Agree with Beach bathroom. This is at the base of your stairs, so any weight on the stairs is going to be loaded at that point.
Do not use the stairs until you have had them professionally looked at.

Any type of paint will not help at all. The stairs are structurally unsound!

Thank you. What sort of professional do you recommend we call in? We are in Darwin?

Structural Engineer.....Local Council, if not able to help you may be able to suggest an engineer.

My thoughts

Darwin. wet, high humidity, steel has rusted from the inside, thickness possibly greatly reduced in thickness and strength.

Thanks very much again. Also wondering what kind of tradees do this kind of work ? Will make inquires about a structural engineer but suspect may be hard to find and what kind of person would carry out repairs?

Darwin is a city with lots of new developments. Contact a builder, any builder, and they will put you in touch with the necessary professional. They might even do the job for you.

Thank you !