It looks very much like the one shown third from the left here:
http://www.johnsonreferencebooks.com/catalogue/accout/portepeesknots/19242.jpg" onclick="window.open(this.href);return false;
The items are described here:
http://www.johnsonreferencebooks.com/catalogue/accout/portepeesknots/index.html" onclick="window.open(this.href);return false;
And then there's this picture on a German site:
http://www.jugendclub-roitzsch.de/wbb3/index.php?page=Attachment&attachmentID=4734&h=086630f354a5fe978650e015ad5d6502e5992594" onclick="window.open(this.href);return false;
The eBay item looks very well preserved, doesn't it? :-"