I like your style Matt: looks great. When I saw the piccies I immediately thought "What about a cushion?", but you covered that straight away! It would be a pity if you couldn't see that lovely wood finish though.
Re Morton's comment: it would be easy enough to drill a hole in the shelf for a cup holder...
(Or eyepieces for that matter!)
Keep up the good work: and I look forward to seeing the eventual seat that you make.
All the best,
Dean