Not sure where to put this so it's here.
I re-fitted my newly modified John Moorehouse seat(s) to my ST 1300 last night and whilst they look good, and feel good on my bum from just sitting on it, I haven't had time to go for a ride yet to see what they feel like on the road.
Here's a couple of pics of the two parts of the seat, both modified.
From comments from John and others it would appear that the seat(s) take about 1,000-1,500 to 'bed-in' and shape themselves to the posterior plonked on them, so I'll let you all know later how well this process goes.