I broke my usual "rule of thumb" -- don't bid over 2/3 of CV -- on this one. But one would have to understand my main collection of US airmails to understand what a unique opportunity this was. I have a collection housed in two Linder albums, in which I've interleaved the White Ace pages for singles with White Ace pages for plate blocks. The collection of mint singles is complete, including the Zepps. I have a complete collection of plate blocks (or panes and line pairs for booklet and coil stamps) for everything except C1-C6 and the Zepps. On the back of pages facing the plate blocks (or panes or line pairs) I have mounted an FDC for each stamp. For everything after C31, I have an FDC that has a plate block, line pair or pane. I have plate blocks covers for C25-C31, but that's a different story.
So when a bunch of plate block FDC's came up for auction on
ebay, I went after them. I was outbid for the C24 cover, but won auctions for nice plate block FDC's for C20, C21 and C22. I already had an FDC with plate block for C17. So gradually, I'm filling in some "holes" as far as plate block FDC's go, for the airmails C24 and under.
Only in my dreams, when I win the lottery, would I imagine ever owning plate block FDC's of C1-C6 or the Zepps. Well, C18 might be possible, under the right conditions.
But all in all, the two albums hosting this collection have a pretty good representation of "better" FDC's.