Bidspirit auction | British Commonwealth - Malayan States

British Commonwealth - Malayan States - Perak - JAPANESE OCCUPATION: 1942, two stamps with inverted black overprint (type 1) on Sultan Iskandar 3c green and 8c scarlet, first one has slightly rounded bottom left corner, both with large part of OG, F/VF, this errors are not listed either in Scott or Gibbons Cat., individual RPS certificates, Est. $300-$400, Sc. #N3, N6 var