Diamondback Tonneau Question

I purchased a new 2018 Limited with the short bed. Previously, I had a 2007 with the long bed. I still have the Diamondback Tonneau cover for the long bed with the small headache rack.

I want to purchase a new short bed Diamondback cover.

I also would like to use my small headache rack if possible.

Can someone inform me of the measurement of their short bed Diamondback cover along the top where a rack would sit?

I called the company and they insist the rack would not fit but do not sell individual racks; so I am a little confused.

Attached is the current picture of my cover; pretend truck is invisible.

 

The outside widths of the Tacoma bed at the cab

• 2005-2015: 65"
• 2016+: 63.25"

My guess is that the old headache rack will be 1.75" too wide.

 

I'll measure this when i get home in a couple hours. (Night shift)

 

On the flat top of the cover before or bevels down top must the bed, it measures 60" even.

The top is 63" wide if adding the beveled down sides also. Make sense?

 

Oddly, this thing isn't a perfect square. Back at the tailgate, it's only 57.5" on the flat top. Never knew that.

 

Thank you. I was afraid it might not fit. I tried to put the cover on the new truck to see.
I was just curious if I had only purchased another long bed, maybe my cover would have fit. It is too long by about 12"; about a long bed dimension.
Now I am thinking of cutting 6" off each panel then ..