I recently purchased this Antigua 1p Victoria, vermilion, perf. 12 1/2, watermarked Crown and "CC" (Scott 6), from an APS sales circuit. The watermark is inverted.


The 2015 Scott Classic Specialized Catalogue makes no mention of an inverted watermark variety for this stamp. What does SG say about this stamp, and what is its catalog value? My 2015 says $26.50 for the basic stamp.
As always, all responses will be greatly appreciated.
Robert