Technical Early Ford brake drums?

Can anyone tell me what two different year brake drums I have. They both were on the front of my 1941 ford car. I believe the top drum is original ‘41 ford but not sure of the other drum? Later Ford?

 

I think the top one is early and used a screw in cap , and the bottom one is later ..maybe 46-48.

 

39's were wide 5.

 

That statement is a little confusing. When each year drum is ***embled on its corresponding same year hub, then they can be used interchangeably. But you can't mix the drums and hubs up.

 

Thanks everyone for the information.