Obviously this never went through the mail; presumably it was enclosed in a letter, a magazine issue, or given out as a promotional piece.
The Philatelic West ceased publication in 1930, so presumably this parcel tag was created in the teens or 1920s.
So most definitely NOT an actual improper use of a revenue stamp as postage, but it ties to my collecting interests nonetheless.
P.S. Love the British Guiana fantasy cancel.