IS 2A016 new project

I have just got a Continental 2A016 engine as a new project. It looks like it has has very little use if any at all and has been sat in a barn for a long time.  It has alloy shrouds which have some surface corrosion in parts. Best guessing they are aluminium based because of the powdery deposits, it's not magnetic at all. I am going to wire brush the effected areas to get back to the bare metal. I may paint it but I may keep it as it is so primers are out. Can anyone suggest something to prevent the corrosion coming back please.

If you paint them use an etch primer, it acid etches into the surface to give a key so you can then paint, ordinary paint on Aluminium will not stick, otherwise if you leave the surface bare use the lacquer that is used on bare motor cycle casings.  

Maryalice

Some photos would be nice.

MaryAlice, Thanks for the info, the more I look at it the more I am leaning towards painting it, It stood in a barn for a lot of years , as you can see there has been quite a bit of oxidisation.
I'm still trying to get all the straw from behind the covers.