Seriously, I have done two of the English style buttplates and they are a little more tedious than , say, a Tennessee buttplate. Just go slow and have the butt profile as close to final profile as possible before starting.
The first one I did was on a .54 caliber "express rifle" and it turned out really good. The transition at the heel is the trickiest part. About two years after the rifle was finished, the owner cut it off and added a recoil pad to the rifle- I would gladly have murdered him.
Be Well,
Bill Ridout