Hi all, I found a stack of about 100 of these philatelic covers from GB in my collection, given to me about 25 years ago. I really don't know anything about them. I collect mostly Canada so these look different. I am astonished by the variety of postmarks commemorating all kinds of local events.
Can anyone tell me more about these types of covers? I'm looking to get rid of them, but first want to know more about what I have here.