Aluminum rivets are available at most hardware stores.
You will need two sizes 3/16 x 3/8 to 1/2 inch grip range and 3/16 x 1/4 grip range.
If you are replacing the upper cabinet rivets you will need Acorn nuts.
It the curtain rod brackets are loose you need 1/8 x 1/2 inch grip range.
If you need snap caps and bases go to prodec.com and click on snapcaps.
he page that comes up will show both sizes you need.
It's much less expensive ordering the caps from prodec than Scamp
A hand rivet gun is all you need and are also available from most hardware stores.
Good luck, several years ago I bought a 16' Scamp
that needed every rivet replaced.