[DCRM-L] Seller's stamp vs. vendor's stamp (etc.)

[Cawelti, Andrea]

Greetings, fellow rare and otherwise confusing materials catalogers, I'm working on a collection of music in which it would be useful to record music seller's stamps which appear on title or caption.  Does anyone have strong feelings about the vocabulary of these animals?  I don't see anything in the usual sources (but am no doubt looking in the wrong place, sorry in advance) but am sure that others have more experience on this one.  These stamps are such a common occurrence that there just must be something I'm missing here.  In the absence of other advice, am thinking something like this:
561: Music seller's stamp at foot of imprint: J. Ewer & Co., 1 Bow-Church Yd. Cheapside.
655 7 Sellers' stamps. $2 local
But would be grateful for wiser guidance.
Thoughts?
andrea
-- 
(Ms.) Andrea Cawelti 
Ward Music Cataloger 
Houghton Library 
Harvard University 
Cambridge, MA  02138 

Phone: (617) 998-5259
FAX: (617) 495-1376 
E-mail: cawelti at fas.harvard.edu