First AC may be my last

I reconnected fuel line, opened valve to sediment bowl, opened drain on bottom of carb, gas immediately began flowing through at a steady stream. I was counting 30 seconds and as I got to 20 the stream became intermittent and was just a drip by 25.

If it still stops flowing after 20 to 25 seconds disconnect gas line from carb and verify you have good flow to carb. Make sure you also verify it's not fuel cap as Dave said. Before blaming it on carb, always make sure you have verified good fuel supply to carb.

UPDATE -- I was motivated by this panel and bought a service manual online (from the place mentioned above). I got a digital copy and it is a pdf of the typewritten manual -- very cool (old) looking. I read about and studied the carburetor for a few days. I decided I was ready to proceed, with my first foray being to take the fuel line from the carb and see if gas flowed etc. I had stopped at the parts place and learned that a carb kit would cost me $20 and was mentally preparing to go step by step through the process. The parts house wanted the number off the carb so I came to farm and - yep -- the number is on the back side of the carb.  Backed tractor into barn (died, bucked and spit at me for the 5 to 8 minutes it took for that 1 minute trip), found a black mat from back of a Ford Escape and put it on ground under carb (for any stray pieces that might fall). I went to garage (50 feet away) looking for some box end wrenches. When I returned the barn lot gate was wide open (it was very windy) and as I was calling my dog and starting to close the gate, Big Al started "on his own"!  HOLY CRAP! - Now I have a GHOST tractor!! -- But wait -- someone is in the seat - my tractor guy came to pick up BA and take him to his little shop. I told him all I had done, he agreed that Al was not getting fuel properly (died, bucked and spit with him until he got on the downhill drive and coasted down to his waiting trailer) and  -- 3 days later I hear Big Al coming up the driveway (in my office on second floor of farm house). By time I get down there TG is walking back down to his truck - so I called him later and he told me that he found a "whirleybird" (apparently that's what they call maple leaves in Kentucky) stuck in the inlet to the sediment bowl. He drained gas tank, looked around with a flex light and said it was rust free. However, the carburetor, in which he had put a new kit before I bought BA last November, was "rusty" and filthy. He bought a new kit and installed that, made sure all the gas was flowing and I got the pasture mowed. I asked him what I owed him and he said, "well, the kit cost me $20 and probably $20 for me coming to get it and bring it back" -- Sounded a bit low to me -- I gave him $60.  

Ok -- so now we move forward. Big Al pulled the six foot mower up and down my hills, through some taller grass and got done. Upon first starting up it sounded to me like he was "missing" just a touch, kinda warmed out of that and mowed like a champ - til the third day. On the third day, when he was having to navigate the steepest part of the hill he began to act like he was going to choke down, I noticed that the temp gauge was right at the top of the green (right on line between green and "hot white".  I see no other evidence that he is overheating (no steam, hear now leaks, etc.) I keep watching, he kinda clears his throat and I was able to finish the mowing (only had about 10 minutes to finish). About 4 days later I mowed around the barn for only about 40 minutes -- he did ok with a couple of "coughs".  I bought 4 Autolite 295 plugs back in the beginning of this saga as was suggested earlier in this thread. I'm thinking that a change of spark plugs might help if the carb was that "mucked up"?  

I believe if you have old tractors there will always be something to fix on them. But there is nothing more gratifying when you fix the problem and it works. Don't be afraid to ask the people here for help and advice as they are more than willing. One has to love the old tractors or why would you have one! (just my thought)