Big holes drilled in my brake shoes...why?

[Art Bailey]

Hey All,

 

I picked up some NOS brake shoes to rivet onto my '48 DeSoto's shoes. However, the majority of them have four big holes drilled at one end of each shoe, right in an area where I  need to place two rivets, like the one on the right in this picture: 

 

 

Curious to know...why?  

 

Thanks,

Art

[MarcDeSoto]

Look like the two rivets are below the holes.  I have never seen those holes.  Could it be for heat dissapation?  

[Dodgeb4ya]

I have seen the same holes over the years...don't know what they are there for either.