How was the 'Common Lectionary' estabilshed, and what lead to it's
being revised.  Which denominations follow the common lectionary, and
which the revised common lectionary?

How were the international sunday school lessons established - and how
do they differ from the revised lectionary.  Which denominations
follow / use the international sunday school lessons?  Do any
denominations use both?

It is likely that this will take quite a bit more research than most
Researchers would be willing to devote to a $5 question.