Afb carb restoration
One possible problem is sealing the pores in the carb casting. When the carb was first manufactured, the casting underwent an impregnation process using a special sealant and vacuum process. The proces filled microscopic voids in the metal. With age, repeated cleanings, and the corrosive nature of modern gasoline with alcohol, most original castings leak fuel internally.
There are companies that seal castings. I have not used them, but would expect the cost to be greater than a new carb.