Well as the weathers nice,
I thought i'd revisit this
I took the seats off and made up a new seat using 15mm melamine ( all i had handy lol)
I used the rear seat locator bar as the back, and had to fit it using the fuse holder as the front stop
( i removed the small loom and tucked it out of the way )
This give me a new seat height of 740mm near on 29" which given i have an inside leg of 29"
I could get both balls of the foot on the deck

and it felt like i was sitting in the bike not on it if that makes sense
so looking at my original measurements, i need to loose 40mm about another 1.5",
And slim the seat width to 240 - 270 270 we know already works
Question is, am i going to get another 1.5" out of the seat, and keep it long distance comfy
Would be handy if the OP could get some good pics and measurements up of the new seat