Hello..
I need some tips as to how and accomplish the following:

I am attempting to restore an antique radio which used an aluminum
chassis ........................

A very general rule which is applied to antique furniture restoration is this.
Accept the fact that an old piece which has been used will show some wear and
tear, the less the better. It is better to live with cosmetic damage than to
attempt refinishing. Never strip and refinish. If damage is so severe that
the piece cannot be used or displayed, as if a leg were broken off a chest of
drawers, then carefully replace the leg, with a similat part, but put emphasis
on doing a quality repair rather than concealing the fact that the piece was
damaged.

In your case, it would be more important to preserve the original surface
condition and the silk-screen lettering than to disguise the fact that holes
were made by someone in the past. As another lister has suggested, go to Radio
Shack and buy a couple of plastic plugs for the holes.

A few scars are witness to a useful life. A refinished antique is like an
80-year-old floozy with a brand new boob job.