Handel, George Frideric.

2 works in one volume, first edition of "premier volume", 94 and 83 pages, oblong 4to (c.22.5 x 29cms), engraved titles, privilege (14 June 1720), engraved preface by Handel, and engraved music throughout, contemporary manuscript editorial corrections to "premier volume" (pp. 14, 16 (not in Smith), 31, 44, 58, 62 (2), 66, and 70), contemporary stamp to first title ("N.10"), eighteenth-century marbled boards, rebacked and re-cornered, retaining red-gilt label on spine, modern slip-case, some show-through (or off-setting?) in the "premier volume", slight worming to first few leaves, some light staining,

Premier volume: Smith no.1; RISM H 1430; Hirsch, iii 241; Hoboken 168 (plates 48 and 49, "N.20"); J. Simon et al, Handel. A Celebration of his Life and Times (National Portrait Gallery exhibition catalogue 1985), no.74 ("N.45")--Second volume: Smith no.5

Condition is described in the main body of the cataloguing, where appropriate
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

Rare: we have no record of Handel's original edition of his harpsichord works appearing at auction for twenty years. 

This edition was probably the only volume of Handel's music ever published under the direct supervision of the composer.  He had these "lessons" printed (as he notes in his engraved preface) "because Surrepticious and incorrect copies of them have got abroad".   This earliest issue contains corrections in manuscript, which were almost certainly ordered by Handel himself; these are incorporated in the plates in later editions.  On later issues there are also changes to the title and to Handel's preface.  Each copy bears a number stamped at the top left of the title page, and "N.10" is the lowest we have seen for sale.