29 gas tank attachment

[Jerry Kzoo]

I picked up a 29 cowl and was wondering about the gas tank attachment to it. It says to use 1/4-20 bolts to attach the front and back flanges and clamps for the sides. I am wondering why the use of clamps when there seems to be 5 matching holes on both pieces on each side. I am not familiar with the clamps, but do they locate and nest in these holes? This cowl did not come with these clamps, but it is from a Coupe or Tudor I think.

Thanks, Jerry