I had asked this same question about two years ago on a different GW website.
If you get into the actual physics/analysis of the airstream passing the chokeplates and the purpose they serve, as long as the plates cover as much of the throat of the carb as possible, and don't stick or bind in anyway, they are fine.... the choke shafts and plates are outside of the dynamic areas of fuel/air mixing... kind of like the wire mesh is inside the plenum over each bore... any leaks or play in the shafts will not affect the fuel/air mixtures and will introduce negligible unfiltered air into the intake airstream (this was the basis of my original inquiry on this subject)
Since all the metering jets and slides are on THE OTHER SIDE of the carburetor the choke plates and shafts are not going to affect the running of the bike. (as long as they fully open when the choke knob is pushed in)
If you are concerned that you might have too large a gap for there to be a vacuum differential to be developed on the underside of the choke plate when closed to cause more fuel to be drawn up the enrichment passages (full choke), don't be..... as long as you can freely move the plates and they don't bind up, the felt washers/shaft free play and or any discernible gaps in the plates not fully closing off the throat of the carb are of no consequence... Just pay more attention to all the stuff on the lower down parts of the carbs and make sure ALL the passages are clean, clear and fully open (I found that using dental brushes or "plaque removers" that the orthodontist gave my kids when they had braces on, or at your local CVS or other drug store in the dental hygiene aisle) was a great way to get into all the tight spots that I couldn't or wouldn't want to use anything sharp or damaging on.
Pay close attention to the float levels, as they all need to be as dead on as you can possibly make them to insure proper fuel delivery (some of the passages are fuel height dependent, not just vacuum drawn. Take your time and you will do fine and enjoy the results...
Rich