C-x v g going further back in time?

[Benjamin Rutt]

I love C-x v g in a file managed by CVS, I can see exactly which user
finalized which line of the file, and on which date.  This is
invaluable for answering the question of who to ask about different
lines of code.  However, sometimes that's not enough to find out who
put that line of code there originally, as sometimes people make
whitespace changes, yet C-x v g only shows the last committer of a
line so sometimes the "whitespace changer" is not the "true author" of
that line.  Is there any way to go back in time to see who committed a
given line earlier in time?
-- 
Benjamin