I'm guessing from their location that they were part of a shipping bracket that the dealer forgot to remove.  There was probably a third piece that spanned the two brackets across the type basket to prevent the typebars from hitting the platen while in transit.  Just a guess. 

Pete E. wrote:

I am curious about the sheet metal cover over the idler pulley. 

Seems like a home-made item...???

I had had 2 Electra 220's come across by work bench.  Certainly not enough to know either way...but my 2 machines did not have such.  But then again, my 2 machines could have come with them and were just lost over time in a repair shop...???...

I had a senior "brain fart" moment. There's 3 typewriters on my shop table that are opened up and this one is an "Electra 250". The ones' with the full length bottom rubber bumpers and other features.
Apologies.
THe 250 seems pretty much the same as the 220. I don't know what the differences are.
But, yes, I have several 120, 220, and this 250 and only the 250 had these brackets.
They aren't screwed or bolted on. They just sit in a notch on the side frames with nothing really keeping them there.
Strange.
k

On reassembly, I can't see how these plates have a function. They are not solidly attached to anything. As suggested, perhaps they were originally for shipping from the factory as an inner spacer support for the sliding cover, or some other function.  Oh well.
But, putting anything back together again and having extra parts left over is never a good feeling.. . .  .  
k

Solved:
Found this in the original purchase documents for the typewriter: