I.F.S. Soruth SG 38c Mint 1913 1a on 4a red surcharge double

1913 1a on 4a red on laid paper showing part of papermaker's ornate 'Leopard' (?) watermark, error Surcharge double, from pos. 5 on the sheet with intact margins, fresh unused (without gum, as issued). Trivial perf separation at right mentioned strictly for accuracy, otherwise very fine and rare. P256001400