gandalf99,
First of all, welcome to the forum!
Quote:
I still have one doubt: how to distinguish Typo 1953 values from reprinted 1957 ones (Michel 405 to 422).
As far as I know, only the reprints of the first issue (Mi 362 - 379) can be easily distinguished. (The position of the letter "E" in "Deutsche" that was mentioned earlier.)
Reprints of later issues can sometimes be determined by the cancellation. This link was provided earlier:
http://www.jaypex.com/Germany/DDR5YearPlan.htmIf you scroll to the bottom of the page, you can see cancellations that were used for reprints. They are also listed in Michel Spezial.
Of course, all mint ("Postfrisch") copies are originals.
Personally, I consider all cancelled stamps of later issues 2 - 7 to be reprints unless I can be certain that they are not one of the reprint cancellations. I side-step the problem by collecting only mint.

They aren't expensive unless you choose to collect watermark variations.
Dan
