Fakes were actually more prominent in the past it seems, back in the glory days of early stamp collecting. My inherited classic WW collection contained many fakes/unauthorized reprints etc. from the 1910s/1920s period.
Many. many fakes were produced shortly after the actual stamps came out. They were made to fool the PO, to sell to dealers (packet makers), and to sell to collectors. So old collections are just as likely to have some fakes.
Ikuna-this stamp has not been forged. Because during this period the value is higher for canceled stamps there are many stamps with fake cancellations.Not for this stamp. You have information from the specialized Michel catalog.