What Year Are These German Stamps?

Does anyone know the year of these?

circa 1880. I'm not with my catalogues at this moment, so I cannot give you specifics. Note that some have pfennig and some have pfennige inscriptions.

Thanks again, Cjd!

The 10 Pfennige is from 1875, Scott 31 cat 85c. The 20 & 50 Pfennig are from 1880, Scott 40 & 42, cat 75c each. The condition of your examples is unfortunately not the greatest.

Singular: der Pfennig [the penny]
Plural: die Pfennige [the pennies]

So why 10 Pfennige versus 20 Pfennig and 50 Pfennig?????

Just as we refer to the Great Britain 2d Blue as the Two Penny Blue and not the Two Pennies Blue, in German 20 Pfennig is perfectly legitimate. It's really an adjectival usage--we mean "die zwanzig pfennig Briefmarke".

That's also the colloquial use when quoting a price: "Was kosten die Gurken heute? Zwanzig Pfennig, heute. Gestern war es achtzehn Pfennig." (What do the cucumbers cost today? Twenty penny. Yesterday they were eighteen penny."

But if you have 20 pennies lying on a table, you would say "Da sieht man zwanzig Pfennige liegend." ("One sees twenty pennies there lying there.")

But one may also view the inscription as a kind of declarative sentence: Diese Marke hat den Wert von zwanzig Pfennige (or would it be Pfennigen because von takes the dative?) I assume that's why they issued the ones with the "e" on the end.

But perhaps there's a better explanation. These are my
off the top of the head speculations.

Good question.
As a German speaker, when it's the value, you say Pfennig,
when it's the coins, you say Pfennige.