Are All Of These Fiume Stamps Fake?

Try this:
https://stampforgeries.com/forged-s...e-1923-1924/

@perf12 I have actually used this site before, I for whatever reason just never checked if it had a section on Fiume. The blog that has previously been linked to me, I found to be overwhelming, whereas this is laid out much more clearly and is a lot easier for me to understand. By any chance, do you know if the person who is responsible for this site is still active? I tried to contact them in the past, but nothing worked.

you can send them an email . it's indicated on the bottom of the frontpage.
cheers

I did. Multiple times. There are also links to several methods to contact them, such as Facebook, but all of the links are dead. Gmail tells me the email address is not active / not able to receive my emails.