Thanks Mowerfreak , Im actually restoring a cast iron Dawn vice as we speak ( will post some photos next week) and I used this Rustolium and found quite good.

https://www.bunnings.com.au/rust-oleum-340g-gloss-ultra-cover-2x-spray-paint-colonial-red_p1580688

Ive never bought a rust converter, did you use something like this ?

Also on the underside of the deck did you still just use the rust converter plus primer / paint or something else ?

https://www.bunnings.com.au/bondall-250ml-ranex-rustbuster-rust-converter_p1560855

Thanks