(El Dorado) Clarksville, Cal, oval postmark with "Apr 4 /64" manuscript date on 1861 3¢ pink entire to Illinois with pen strokes cancelling the indicium, "Due 6" manuscript marking in the same handwriting as the postmark date so evidently overweight (due 6¢ for a 6¢ underpayment if accidental or due double a 3¢ underpayment if intentional from July 1, 1863, until May 1, 1865), Extremely Fine and scarce, one of the few California fancy postmarks, illustrated in Coburn's Letters of Gold (page 313). Estimate  $500 - 750. $0 (Image)