Hi Andy, just came across your build...looking good...well done!
Don't know if you know but in the UK they were used as courier bikes a lot....I was the mechanic at a firm that ran 20 of them, all doing 6 to 800 miles a week. I always thought they were about the best 250 Honda ever made though they had a reputation for being a bit fragile over here....mainly because of cylinder head problems. Back then it wasn't much of a problem as you'd just stick another one on but guessing now that's not so easy to find one!
So, if you don't mind, a couple of suggestions...frequent oil changes to avoid wear on the cam bearing surfaces and be wary of running weak...the left hand exhaust valve especially can overheat and burn....and if that happens you'll often find the head cracks between the seat and the plug as well.