I tend to use Bilt Hamber Deox Gel on all my rusted parts, automotive, computer or otherwise! It’s a great product that can achieve results like this:

I'm just working through restoring a very rusty old case. On the metal parts I've been using wire brush for light rust, dremmel grinder for deep rust, then a citric acid based rust killer followed by hammerite Krust rust converter (which discolours the case). Knifing putty to smooth if any pitting. Then spray prime and spray finish. I guess it's depends how bad it is. If its hidden around the feet you may not care about the scars etc. or could just smooth an just spray the bottom to even it out.

I've mostly used wheel wire brushes, which you connect to a drill. After the rust is gone, use sandpaper to smooth out the surface until it's shiny again.

You can then repaint it or, if you want to keep the bare metal, add a layer of transparent lacquer.