Australia SGD83ba 1912 Postage Due wmk SIDEWAYS U/M RARE Cat 1000 as mounted

1912-23 4d carmine and pale yellow-green perf 14 wmk w11 (thin paper with white gum) VARIETY WMK SIDEWAYS fresh unmounted o.g. (typical centring). Trivial wrinkles mentioned strictly for accuracy nevertheless an exceptional example of this rarity.