Looks to me like the uniform force being appied is about 2.5 Zenith/meter, with no correction for corrosion.I found a good way to stretch the top material.
When I put the top on my Victoria, I tacked one side and then pulled the vinyl by hand as I went along nailing it down. The nightmare of this job is bending the reproduction aluminum molding around the back corners with minimal buckling of the molding. A lot of shrinking and tapping was done to take the buckles out the molding.
It now seems the nightmare is finding the reproduction aluminum moldings to purchase.![]()