Great Britain Philatelic Society

I have recently acquired a lot of around 100 definitive stamps, both Wilding and Machin, that have been cut off envelopes together with the franking cancellation mark. I was intrigued by the range of postal districts with locations such as Sixmilecross, Garvagh, Warrenpoint etc. They cover the period from the early 1960 into the 1970 and 80s.

I am just wondering how collectable these are? Attached is a sample photograph.

Definitely collectable (some of the offices may have been closed by now), although not much in demand.

There's a listing of Northern Ireland post offices at Ken Smith's "UK Post Offices by County" project:

https://sites.google.com/site/ukpostofficesbycounty/home/northern-ireland

Thank you for the swift reply, this is really helpful. The interest I think is more important than the value.