If you're looking for disguised autobiographies, why not use
Indiscretions?  Or Discretions, for that matter.
 
Also, Eliot may not be a great letter writer as represented by D.D. Paige,
but Valerie's edition of the early letters, published several years ago,
is a wonder.  Remember: the "low" Eliot shows up almost nowhere else.
 
Finally, I have often had to troll through many individual indexes of
published volumes of Pound correspondence looking for a single item.  Any
interest out there in a collective index to Pound's published letters?  It
wouldn't be much work, I guess.  But it may be legally problematic in
terms of publisher rights.
 
Jonathan Gill