The emulsion tubes seem to be the holy grail part. I can't make heads or tails of the needle part numbers, or even figure out which type would be a direct replacement.

http://www.motorcyclecarbs.com/Keihin_Jet_Needle_Selection_Gu_W281C495.cfm
http://www.motorcyclecarbs.com/KEIHIN_N427-48_OEM_Jet_Needle__W252C1274.cfm.

Anyone with ideas on how to decipher this? I don't have any extra needles to check the numbers against.