Auction 260 March 2025 - Day 3 Netherlands and colonies single lots

General Post Office 1953, 30 cent in orange (statt red), full double sheet of 400 with 20 horizontal AND 20 vertical gutter pairs, without margin printings,  as far as we know the only proofsheet in this color with written Gezien (seen) 28/11 52 and fiat tjetak 1/12 52, both with paraph, only in margin a few brown spots, VERY RARE, Prangko 107, color not mentioned