The whole "46 lettered" thing means that there were 46 deluxe edition books made (deluxe meaning with painting or print); 26 of which were actually lettered and 20 more were divided up into "Publisher's Copy," "Printer's Copy," usually several "Presentation Copy," etc. The wording in the BSP colophons is typically somewhat wonky. For example, "126 numbered copies, hand-bound in boards by Earle Grey, each with an original..." means 100 numbered copies plus 26 lettered copies. In this wording, the presentation copies, printer's copy, etc. were not accounted for in the colophon (your Dorbin book is a rather early publication, so the basic scheme hadn't been set in motion yet). Those more accurate counts come from Krumhansl.
Anyway, that's a nice group. Of them, the Dorbin with art (probably a watercolor) and Horsemeat stand out. The Dorbin book isn't among the more pricey books with art, but art is good. As
roni said, pictures would help, as condition is everything. You can upload photos directly here (no need for an image hosting service).