Technical Need help with ID on this part. Could anyone help with year and model on these top pieces?

Need help with ID on this part. Could anyone help with year and model on these top pieces?

 

Do you have better pic of the mounting brackets and what is the distant from bolt center to bolt center?
cast steel ? or made of sheet metal with a seam on the back side ?

later kb

 

KB, the entire ***embly including the mounting brackets are steel. The base onf the bracket is 3" wide and the bolt holes for that are 2" on center

 

Ok , what is the distant from the center of the knobs ?

 

Model A Sport Coupe landau bars, got a set off a 30 in the garage I can measure if you get a center to center on the point where they mount to the brackets. Not sure if the length is different between the 28-29 and the 30-31.

 

the measurement for the knobs on center is 21"

 

Just measured the set in the garage and the centers on them is 21" and according to a Model A site 28-31 are all the same length. They came off my 30 Sport Coupe, left them off since I never liked the look of them.