Are These Nicaragua Proofs?

I found these in a glassine between the pages of Nicaragua and wonder what they are?

I assume they are cut-outs from postal stationeries

No ,they are not proofs and they are not from Postal stationary . These are reprints made for the philatelic trade .I have four or five sets of them . One set in each of my Worldwide Collection on album pages and here is two sets in my stockbooks ,maybe one or two sets on dealer cards filed away years ago .Very common if you purchased junk lots at stamp auctions years ago .

You're right,margins at top could not be so wide on postal stationeries

These are "Seebeck" reprints made by Nicholas Seebeck's Hamilton Bank Note printing firm:

https://en.wikipedia.org/wiki/Nicholas_F._Seebeck

I guess this guy is too optimistic;

To keep this subject going here is a page from a old stamp album{1900's } . I have to guess that the guy who was making and selling these reprints. Made sure he had a market for his stuff by getting album makers to include his stuff into the stamp albums .

floortrader and nigelc: thanks for your clarifying updates. I have some of these Nicaragua items, which I had assumed were from either postal stationary (envelopes) or postal cards.

I appreciate the additional knowledge. Now that my downsizing from a former world wide collection is almost done, I'm turning attention to re-organization of the remaining stuff. I have a couple collections of Nicaragua that I retained. But who knows when I'll get to them. Too many collections from countries I specialize in, and Nicaragua is a secondary interest.