<VV> Hole in the throat?

[Grant Young]

Just checking to see if anyone knows why quite a few owners of early models drilled a hole in the venturi
of their carburetors? Perhaps there was a misunderstanding about drilling a hole in the very early (non-chipped)
throttle plates to improve their idle quality? I have known of attempts at this when engines were over-carbureted
or when non-stock carbs were used, but continue to see a dozen or more of these holey carbs each year. They are 
too inconsistent in size and location to think it was a dealer thing. I have never seen one in a later model carb. 
I plug them with liquid metal for the rebuild, but would like to know the why.
Thanks,
The Carbmeister