Frankrijk 1870/1870 - Yvert 38f: Pair of 38 with “4” retouched with RR anchor postmark. - Yvert 38f

Pair of 38f with retouched "4" and cancelled with an anchor postmark.
Large rarity of French philately.
Certificate.
No value listed (estimated value €13,000)!
The 38f with the regular cancellation is valued at €4,000 but the anchor cancellation is three times more valuable than the regular version!
An extra-rare combo.
One corner is round, otherwise in F condition with a low price for such an exceptional specimen!