Chris, I completely understand how upset you are! This could be a nightmare given you had it shipped from the US. However, there is a very good chance that it can be resolved without great expense.
While I couldn't really see anything from your video, it did answer two questions for me. You did retain the tall valve covers that came with the engine and you are running a pcv valve. Good. Since the
oil is in the tailpipe, we can safely assume it is inthe combustion chamber. But is it in all of them? You have enough miles to read the plugs. Is it equal in all or are there one or more cylinders affected. Check the plugs for
oil fouling. Once you have isolated the cylinders, you need to determine the source. Really only three: Valve seals, rings, or intake. Start with the inspection of the intake runners and then pull the valve covers and visually inspect the seals. All of this is about an hours work and should give you a good idea of the next steps. Good luck and keep us posted.
Mark