German Stamps Identification

From several mixtures and trades I've accumulated some late 20th-early 21st century stamps of Berlin and Germany that puzzle me as to their status or purpose. I think there must be a simple explanation, although as far as I can discover the Scott catalog is no help. I'm pretty confident someone in the community will be able to enlighten me.

Two of these Germany stamps are of designs with Scott numbers but are imperforate (Scott lists only perforated versions), and they are also printed on paper that's more like the weight of computer paper than the heavier stock stamps usually are printed on. The SC numbers are 1992 and 2086/2087.

Two other stamps feature drawn representations of buildings--a Berlin issue of Charlottenburg Palace, and one issued by Germany of Schloss Sanssouci--and neither has a value (a monetary number) that is intrinsic in the overall design, but rather one that has been imprinted on the stamp later, the Berlin stamp DBP*280*, the German one DBP**40*. They are both imperforate with two small semi-cicles clipped from the top and bottom margins.

I have a few other similar German issues that puzzle me but possibly explanation(s) of the above stamps will shed light on these as well. If that turns out not to be so, I'll ask about them in a subsequent posting. Thanks for any help.

*** Moved by Staff to a more appropriate forum. ***

Can you put some scan ? Especially if you want to make few of those request..

The last two stamps are automat stamps. The value is imprinted when purchased.

An example:

Yes, please post a picture. It is not good to just be guessing at stuff!

Peter

Is this the design for the German stamp you mention in the second paragraph?



These were year 2000 Europa stamps. I wonder if some were printed imperforate for collectors.

EDIT: There is mention here of an imperforate variety of this stamp that seems to be prized. Hang on to them! http://www.europastudyunit.org/nl/en370

The imperfs may be cut-outs from postal stationery. Here's a stamped envelope with an imprint similar to Scott 1992.



Regards, Robert

Thanks, KGB--your illustrations nailed exactly the stamps I was talking about. I had suspected that the imprinted-later stamps came from some kind of machine, with the purchaser indicating the denomination wanted, and I'm glad to have that intuition confirmed. And thanks to you too, Trainwreck: I'm virtually certain now the imperforate squares of Scott 1992 and 2086 have been cut from postal stationery. I don't imagine the postal stationery imperforate version of the EU common issue of 2000 is the high-value one you cited.

The collegiality of Stamp Community has again been splendidly affirmed! Many thanks.