On the basis of your earlier posts if you follow the legal requirements, such as airbags had to be an option, remove all the bits then why to you need the airbag removal to be engineered.
Surely the vehicle is back as built as a standard non optioned vehicle and meets all ADRs. If there is anything in the vehicle documents or tags such as compliance plates then I could understand the engineering requirement.
Good luck with it.
Garry

