I don't think you are going to find that in the public domain for a new Canter.
In the States, there is organisation called SEMA (Specialty Equipment Manufacturer's Association). Members have the ability to work with OEM's to develop products, get early release data, attend special events, etc.
So, if you want to build a bumper for a 2016 Ford Superduty pickup and you have a certain membership package with SEMA, you can get the CAD drawings from Ford to ensure proper bracket placement for the bumper, for example.
I doubt they are going to hand out drawings for an entire truck or chassis and I would not expect MFTB to be inclined to share much of anything since there is such a small market in the States. I am not trying to rain on your parade, but that has been my experience in the past and I have friends who are SEMA members. It is tough even for them to get everything they need.
Maybe you can find something similar in the UK.