Lot
859 
Mexico, 1866, 7c lilac gray, San Luis Potosi, horizontal pair, in combination with 1866, 13c blue + 25c buff, cons 58-1866, all with ample to large margins, on 1866 folded letter to Celaya tied by San Luis Potosi cds's, Extremely Fine, a most remarkable rarity as probably no more than 5 tricolor covers are known; with 1998 Jaretzky and 2016 MEPSI certificates. Scott No. 26-28 Estimate $7,500 - 10,000.
A UNIQUE THREE-COLOR COMBINATION OF THE 1866 MAXIMILIAN ISSUE.