I read this book first some thirty years ago, and then was reminded of it while reading Tom Phillips' Truth. Fortunately, this book turned out to be available second-hand at an affordable price, and I was happy to return to it. I was reminded of it because the books cover related themes, but De Verlakkers -- an acceptable translation would be The Tricksters -- specifically covers literary falsification and mystification. (It was reprinted in 2009 under a different title.)
In his introduction, Wim Zaal happens to remark that people's tastes change over time, and a work which greatly moved you in your youth, may be disappointing when viewed at a later age. But I think this book stood the test of time, even if it was shorter than I remembered it to be. I’d suggest two reasons for that: First, Wim Zaal did not write about commonplace urban legends, but about literary fraud, a subject which as writer and editor he understood very well. And second, he is a good writer, able to embed his sense of humor in well-timed, cutting sentences. For those with a classical education: Zaal's mischievous irony reminds me of Tacitus.
He covered a wide range of frauds, cheats and practical jokers. In these pages we find the medieval Donatio Constatini, the elaborate works of the fake "Formosan" George Psalmanazar, the ridiculous verse of the non-existent poet P. van Os jr., the romantic and very successful contributions of Chatterton and Macpherson, the bizarre Oera Linda Bok, the pseudo-Shakespeare play Vortigern, of course the infamous forged diaries of Hitler, and many, many more. Because there is so much to account for in a short book, most of these pass by at speed, in a few short paragraphs. A handful more notorious cases are deemed worthy of a longer section.
In his introduction, the author assures us that the resisted the urge to insert a mystification of his own, mostly because he was concerned that it would not be discovered for many years. (He has the discouraging example of Petrus Borel, who was unwise enough to publish his own obituary, twenty-five years before his actual death.) Nevertheless, as this was published in 1991, not everything in it can be accepted today without checking. The doubts about the works of Mikhail Sholokhov, for example, seem to have been largely removed. But this book is still great fun.