Collecting Aerograms/Air Letters

I recently bought a lot of stamps. In the lot was an bunch of air letter stamps that had been cut from the actual letter. The "stamp" has plenty of writing, yet it is simply the stamp portion of the whole letter.

Are these worth anything or would collectors only want the whole envelope?

Is there any market for these simple "stamps" only?

Thanks to anyone who responds!

In general, we look for the complete item. I've some, circulated British airletters. As for the "stamp", it doesn't interest me. But... who knows... some people might think otherwise...

What you call 'simple stamps,' generally, are called cut-squares or cut-outs by collectors. These used to be popular, but no longer are. Of course, there always will be some collectors. Being from air letters, they will be modern. That makes them even more fringe items.
I doubt there will be any value in them, except for the very rare ones and to such a specialised collector who has not yet got them. Maybe an aerophilately society can tell you more.