So, on rechecking with the Tow Bar company, they were initially confident but digging deeper have established that, unless tow bar preparation was done during the build, it is not an easy job to install an after market tow bar. After going back to the dealer I bought the car from, we agreed on 3 options. Return the car, swap the car for one with either a tow bar or at least the preparation or they fit the tow bar at cost. They would do any of the 3, so in the end we plumped for option no. 3. They would fit the tow-bar. This included them picking up the car from my house some 134 miles away, leaving a courtesy car for 2 days, and then dropping the car back when completed.
The price - £830 pounds - which is allegedly is below their cost price with no labour charge. Still out of pocket compered to after market, but at least the benefit of a dealer completed warranty.
Why or Why has Skoda made it this difficult and expensive to get a simple job of a tow-bar fitted!
Thanks to everyone for their comments / feedback. Invaluable in this instance.