Great work Antony - I so wish I was doing DD but nevermind....
  Carbs - glad you got them looking good, mine had just a much gunge in them after being stored for '6 months' before I bought it (900ss).
 The brass tube you mentioned I think is the base of the emulsion tube that needs careful inspection sadly,...... 
 American - but check out some of the links on the left here: 
http://66.47.68.116  Just an idea about the choke cable etc - my trackbike has a simple cable tie sticking out under the tank - I'm sure the same system would work easily for our carbs as well - you might need to link two cable ties together but, its cheap and cheerful! 
 Cant remember DD rules - but quite surprised you didnt go for a dynojet kit when going for a big-bore as well?  
Fastners: Ebay is good for all sorts of stuff but its worth while hunting down some good local faster / nut and bolt specialists.....here is my local one that has been SUPERB so far...  
http://www.hawkfast.com  all sorts of weird and cool stuff - just got some stainless washers with rubber backing from them only small sizes but great for fairings / screens. 
 I like the updates - keep em comin please - Frank