A client recently offered me this 1920s UNUSED 4/6d NSW Promissory Note. Complete, with Counter Foil.
This value is not recorded in David Elsmore's very good reference site below. And the ones he does note are pretty pricey even as cut outs, as can be seen. http://www.ozrevenues.com/Revenue-Railway-Local-Perfin-Catalogue/nsw-revenue-catalogue.htm
In pretty decent shape for 85 years old.
I bought it as being unusual and apparently un-recorded.
I seldom use ebay as I have a pretty good handle on value of most things, but this one was tough to even guess at.
A client offered me a fair 3 figure sum for it, and it is his. Noted here for the record and have passed it onto Dave for his site, and for use in 'Stamp News' if he wishes.