[DoctorOetker]

a) I didn't realize how long my post had gotten in the tiny entry box, until after I had posted it... but I will gladly accept the dubious Cup of "Longest readable HN comment in the Guinnes Book of Records"

b) Yes I also think it's very interesting. Initially before coming to these suspicions, I was pissed off about having to dissapoint my sister next time I see her, and the money that was lost buying the SIM card etc, ... but the longer I thought about it and noticed all the inconsistencies in what had happened, it's actually a nice puzzle/gift to receive! Turns out the journey really is the reward after all

c) I have also thought about possible mistakes, but really there is little that can go wrong with a strain gauge! And even if the strain gauge somehow broke, there would have been a long run of letters suddenly appearing for redirection, surely this would be noticed and the letters reweighted... And even if it is incorrectly marked with "insufficient postage" both the sorting which is supposed to redirect it to the return address, as the eventual post man who did not ring failed to see the return address! And with D+1, a delay of ~20 days is totally unheard of (counting up till Nov 7th when the strike was anounced)...

in my response to a sibling of your comment I describe we can simply dissolve a fresh prepaid SIM card to detect the presence of a possible RFID loop antenna