Crash, ok, I may be the only one to say this, but I gotta say it anyways. Dude, I love your little bike man. Like, I really, really like it, I think it's something totally unique, and sure, it may not be super fast, but I'm sure it gets you around alright, right? I have been wanting a bike that is still unique, but still dead nuts reliable that gets awesome gas mileage just for the daily grind, and your machine is basically the best interpretation of that I have seen. Basically, and this isn't knocking any CB550 owners/builders out there, but your CB250 is so much more unique, at least in my opinion. So, I say keep it. You can always find another CB550, so maybe save up some extra cash, wait to buy one, and still keep the 250. Just my 2 cents, whether it be right or wrong, thats my opinion. Good luck with either venture!
Steve