Experimenting and watching the "Raycast" tutorial on YouTube I think I'm getting there.
I now have my object setting to the correct angle as it hits the slope.
This was achieved by storing a Raycast *Hit Point result in a Vector 3 variable and giving the slope a trigger tag. On impact, the event transition then runs a Look At Direction action using the stored variable as the Target Direction and the Object Vector 3 from the controller as the Up Direction.
I guess I just need to do this in reverse on the way down?
If there are any better solutions I'm open for suggestions
Thanks
***Correction, Not Hit Normal (this caused object to rotate wrongly), Hit Point seems to work better but will continue testing!