New Britain, 1915, G.R.I. 1d on 2d on Marshall Islands 20pf Ultramarine, "1" Inverted, setting 2, position 4, violet Rabul oval cancel, rich color, Very Fine, one of two known examples of this rare variety, with the other example unused; with 1989 Holcombe certificate. Scott No. 52a $20,000. Gibbs No. 31b. SG No. 64b  £19,000 ($27,050). THE UNIQUE USED EXAMPLE OF THE G.R.I. 1915 1D ON 2D ON MARSHALL ISLANDS 20PF WITH PROVISIONAL "1" INVERTED. $0 (Image)