Steel Maintenance Van Body Design

I need a complete fabrication design for a 24-foot Tata T19 Ultra that will be converted into a mobile maintenance workshop. I will supply the OEM chassis drawings and all critical dimensions; what I need from you is a set of build-ready plans that a fabricator can follow without guesswork... (Budget: ₹600 - ₹1500 INR, Jobs: 2D Drafting, 3D CAD, AutoCAD, CAD/CAM, Engineering Drawing, Manufacturing Design, Product Design, Solidworks)