Hard cold start- lack of fuel- UPDATED

You've stated what I also think is the cause of the symptoms- the carb bowl is draining. Now, if I can just figure out what's causing it to drain. I'll look down the carb throat after I run it- may help ID the problem. FWIW, I do not get a fuel smell from the oil on the dipstick prior to a cold start, which I would expect if the carb bowl was draining into the cylinders.

I hope/expect there are gasket kits to rebuild a Holley Economaster. Unless it's a lot more complicated than rebuilding a Carter BBD, that job shouldn't take long.