Your tone has improved a lot using the Shilke. What are you now not satisfied about? Just work with it until you reach a stage where you feel it either suits the sound you want, or you've exhausted it enough to realise that you might need something else to get that exact sound you want. Like I wrote before, it seems you are really most of the way there.
By the way, Mark Charig - nice sound. But it just sounds like a trumpet. Those long cornets with no SCs are basically short trumpets anyway. We've had this debate before on the forum.