Now that looks the part
No offense, but it also looks just like every other cafe racer on this site
I assure yuo there's no offence taken here MM
In fact may I just say that I admire the way in which you accept and answer comment and criticism on what is a quite novel, and very interesting project
I'm just going to throw in another suggestion though
Aesthetically I would be aiming to at least have the bottom edge, which ever seat you choose, running
parallel (not necessarily in line) to the bottom edge of the tank, otherwise I feel it will always look as if it hasn't been fitted properly
This is just an observation in the interest of your well being, if you go for the white seat, you should at least try and get a bit of a 'hump' at the back of it, otherwise you'll find yourself hanging onto the bike with your arms, rather than using your butt & legs to hold you in place.
However, it's your bike at the end of the day, so if you're happy with it ( if you're like me, you'll always see room for improvement), nothing else matters