Half way there. I checked for spark using "Atomarc's" advice, and I do have spark! So now, thinking my carb rebuild skills might not have been so great, I loosened the fuel line out of the carb. I turned the engine over a couple of times,and lo and behold, no gas came out. None!
So I'm gonna go through the carb rebuild again, very carefully. I'd appreciate any tips or problems to look for.
On the road again!

1953 GMC half-ton