Another poster in rec.arts.books.tolkien thought, erroneously, that Alan Sauer had claimed there were more than nine Ringwraiths. Mr. Sauer corrected the understanding, but then added this intriguing document to his post.
Of course, one cannot discount MacThornbush's contention, in Sauron: The Circus Years:
"It has, of course, never been successfully proven that the references to 'The Nine' did not actually refer to 'The Nine Companies,' a group of specially trained Black Numenorean commandos; this would necessitate that Sauron be much busier under Orodruin than was previously speculated, but between the initial assays into the craft of Ring-making (c. 1500 S.A.) and the forging of the One (c. 1600 S.A.) lies an entire century, certainly enough time for the forging of however many Rings were needed. While it is certain that the Dark Lord spent much of this time touring Middle-Earth as a lion-tamer (cf. Chapter One: 'Ringling Brothers: Just a Name?') the frequent stops in Mordor, initially thought to be tax writeoffs for the Ringlings-- 'charity shows for the underprivileged minorities' (Undertow, One Form to Rule Them All, p. 586)-- take on an altogether new and sinister meaning."