TomR wrote:

I agree. And, some photos would probably help -- maybe by using a
free image upload site like:
http://tinypic.com/



When the OP wrote that the 4-inch baseboard is okay in some areas,
but and inch below the existing baseboard, it made me suspect that a
wider baseboard is needed. It is possible to use 1"x6" pine as a
baseboard (with top trim and shoe molding on the bottom), or look for
other wider baseboard trim.


About the areas where the concrete wall sticks out a little too far
-- chip it back or grind it back.

Much easier and cleaner to remove suitable material from the back of the
baseboard.