It was hard to see in the Pic, but if the 'mod' was leaf spring clamps. Yes. I used a combo of Home made copies of these offered by Mr. Gasket via the big box speed parts houses.
http://mr-gasket.com/ProductDetails.aspx...;minselection=0
My 68 Would wheel hop the Bias-ply Firestones (Spring wined up) at the end of my dry burnout pior to stagging. I installed these and the hop is gone and they are hidden and an easy bolt on and off as required.
Jim
edit- spelling<JFW>