[Mart]

I couldn't see clearly enough in the video but do you have the correct carb base with the (can't remember the name) valve in it? It looks a bit like a power valve.

Also, probably not directly related, but why does the carb not close properly?

If you suck on the pipe leading to the vac advance does the engine speed change due to the timing advancing/retarding? I'm thinking of it as a way to test the vac diaphrahm.

Edit:
In the second video I can't see two clear squirts of fuel from the accelerator pump. Is it working? Did you make sure the check ball in the small bore at the base of the accelerator pump bore is not stuck?