Sorry, maybe I'm misunderstanding the shift question. From stationary I can select either 1st or Reverse without issue, I can then shift upwards from 1st to 2nd without issue when on the move. The only changing issue emerges with going beyond second. The erratic self-revving is odd, I did wonder if this was the clutch slipping but it's happening when it's under almost no strain.
Thanks for your help, it would be good to get some further thoughts from other members. I'll speak to Dale at Prestige about it, but wanted to at least be more informed on what I'm likely dealing with.