DCSB Bed Dimension Question

So I did some googling and found the bulk of the dimensions I need (as I am currently out of country away from my truck) I was wondering if someone wouldn't mind measuring the bed rail width/Total overall width including the bed rails, as well as the height from the top of the bed to the top of the cab. The dimensions I found are for a 2015 DCSB,

Cargo Area Dimensions:
Cargo Box Length @ Floor (in)60.3
Cargo Box Width @ Wheelhousings (in)41.5
Cargo Box Width @ Top, Rear (in)56.7
Cargo Box (Area) Height (in)18
Cargo Box Width @ Floor (in)56.7

I am coming up with an idea for like a modular type camper shell thing and am trying to do a decent render but I would like some what realistic measurements.

Below is a quick sketch-up of what I was thinking. Trying to DIY it when I get home taking lots of tips from TNTTT.com forums.