Many thanks folks.
The bead wasn't so much because I could as because I just wondered if it would work better with than without and knew I couldn't change my mind once it was off
Having left it on I still wasn't sure so the unanimous verdict on here helped make up my mind and was clearly the right answer. It does look better without. The little finial was going to be a bit longer but there were a couple of cracks which I had to work past leaving a slightly dumpy finial which might suit the box better than the longer one I'd planned!
Wall thickness - to be honest it's not bad (trust me - I've made some right chunky-walled boxes!) but it would be nicer a little bit thinner. Sometimes I'm just a bit over cautious. I'm getting better - that bead looked pretty dreadful and I was nervous of touching it up when the piece was looking good but I took the plunge, tidied both sides, got away with it and learned from it (and will be less reluctant to go the extra half a mill next time!). Equally I will try slimming down the walls a bit next time - mind you with wood that is prone to splitting easily I do worry when it comes to pushing it onto the jamb chuck - I have had a disheartening "click" once or twice as thin walls have cracked on the jamb chuck :-( Having said that the total wall thickness just below the tenon is about 7mm so I could easily loose a mill and still have enough strength unless there's a pre-existing weakness.
As for the grain matching. Somehow it often seems to work out that when a piece is narrowing downwards the grain appears more forgiving. I was fairly careful but probably lost four mill in the parting off and have a five mill tenon so it's probably more luck than judgement as there's a 9 or 10 mill break in the grain pattern. If it was a straight sided box I think you'd really notice it. On this tapering box it seems to work.
I put the tinniest v cut across the joint because the open grain was looking messy and the V just helped to tidy up the edge. I find it very hard to get those in exactly the right spot (and there's not much room for error) On this occasion I seem to have got it right which is heartening - I'm either getting better or luckier!
While it was reversed to take the bead off I took a whisker off the tenon so the lid pops on and off nicely now - no effort but you can feel the air resistance so I'm happy with that.
The finish is just a coat of wood wax 22. It would probably have benefited from a coat of sanding sealer first but I was lazy. I might try another the same and take a bit more time over the finishing.
Fingers crossed that it doesn't move now it's in the house.
Thanks again for all the comments - I'm very happy with my box which has ended up all the better for having its beadectomy.
All the best
Ian