Dear Jim and friends,
I am holding a copy of Vol. V now, as part of my PTS membership. ;-)
Volume V starts on page 1173, and is named Padaruupasuucii (Index Verborum). A vocabulary list? I have a feeling that this is a good resource, only if someone can explain further, in particular how it relates to the other four volumes in Smith's edition, and if it is part of the original Pali text. Thank you.
Further, I just learnt that the book Pali Roots in Saddaniti, by Ven. U Silananda, is available online here:
http://www.btmar.org/files/pdf/dhatu.pdf. Just not sure of any copyright issues, even though this book is already in free circulation.
metta,
Yong Peng.