As I think I have mentioned I got a local Light Engineering firm to create the 'hopper' part of the Horn.

It has been made really well.

Today I attached the 'Wave Guide' to it.
It needs some adjustment and rejigging but here are some results !

As can be seen some further work is required, I might just run it up anyway to see a kind of baseline level.
However I am going to be busy with work and other personal projects but hey progress ! :)