50g - Differences in production batches

[rprosperi]

@Massimo, @Günter, @Voldemar

May I ask where you bought your blue 50g's with serial numbers?

Exact dealer is not important, just enough to understand which channel(s) sold s/n units.

So, I'm looking for answers like these:

-A retail store in Germany/Italy, etc.
-Mail order dealer in Europe
-Mail order dealer from Spain/Portugal (supposedly, these were the only countries authorized to sell them)
-Amazon.com (or local)
-eBay (.de or .it or .com, etc.)
-etc.

Units from 2010-2012 challenge my faulty understanding of when this version was available, perhaps these replies will help refine where.

Thanks