Refurbishing and rebuilding an older carburettor/s is all part of running older classic machines, and can be problematical; trying to tune and balance the old carbs can be fraught with problems associated with wear and/or contamination.
The easiest solution, when new OEM carbs are still available, is to replace the old carb with a new component.
If a new assembly is no longer available, then check our carb schematic. You may be pleasantly surprised at just how many vital (wear prone) spares we are still able to supply?
Alternatives listed below:
Don't waste time trying to refurbish the old item, simply replace it with a brand-new part instead, whilst they are still available.
Add as many parts as you wish to the same shopping cart, new inlet gaskets, nuts, and spring washers for example, and still only pay the same single fixed price shipping cost.