ST HELENA 1864 1d lake DOUBLE SURCHARGE in different sizes Type 4A+C SG 6a mint - Extremely RARE

Extremely rare and intriguing stamp showing DOUBLE surcharge (Very RARE variety on it's own) however, the two surcharges are NOT of the same type and show different lengths. One is Type 4A (measuring 16½mm) and the other measuring about 17½mm, Type 4C.

Repaired at bottom perfs and partially regummed, however, an extremely important St.Helena stamp showing a non recorded variety! Probably a museum piece.