1) Yes, Keith, Dave Evans would have been one of the higher up Ford Engineering guys in that time period.
So your Dad had a blown 1960 Ford Convertible (with a Paxton Supercharger on it). Cool. I am surprised that the GM UAW would have allowed a Ford Vehicle in the GM Hourly parking lot during that time period on 2nd shift.
Blower cars typically need "solid floats" to survive boost. The "black floats" we have today were not around then. The side hung bowls (no race bowls in those days) had pretty strong waffle sided floats which may have been ok for your Dad's low boost paxton deal. If the guy helping your dad, jetted up the carbs pretty good, I could see where the extra fuel from the extra power valve circuits could have caused the issue you mention, even with the blower. Same deal with the progressive linkage.
There is a nice web site that deals with Ford Tri-Power systems here:
http://www.gerlecreek.com/documents/tptechnical.htm
Read through the info and maybe you will recognize a few more names.
A Pic of the prograssive linkage is shown in the 61-63 Ford & Thunderbird 6V Accelerator Linkage and Related Parts topic.
Tom V.