Can Someone Help Identify These Vending Stamps?

Hello everyone. I have known that there are several companies that made vending machine stamps with 1 cent green. I believe these may be Brinkerhoff instead of Shermack or mail o meter company stamps.

I have read that many varieties are suspected or known to have been perforated for philatelic purposes and not used in vending machines.Are these vending machine stamps in popular demand among stamp collectors?



Can anyone direct me about information about these stamps? I would appreciate any assistance. Thank you in advance.
Warm Regards,
Blazenstar

Thank you, 51studebaker for your response. Excellent link and very informative pertaining to the different companies and stamps. Will refer to it if I come across other stamps for any future references.

Warm Regards,

Blazenstar