Rebuilding the Rochester b

I'm working on my 235 inline again and I have two 1958 b series carbs and I want to run a dual carb set up but the one off my original engine is froze up and needs to be rebuilt and the other the base leaks around the throttle shaft how hard is it two rebuild the carbs wat should I do to free the one up and where do I get the parts for them? Or are these carbs worth rebuilding?

 

I currently have a 2gc on it right now but it don't run right