An Australian War museum requested some fired 20mm cases to display with their German FLAK 20mm captured in N. Africa. I sent them 4 typical fired German WW2 era cases. IT TOOK A FULL YEAR TO GET THEM OUT OF CUSTOMS !
Sadly, you do not suprise me. See my post on UPS into Britain. Gradually we are looking at a lockdown on international shipments by stealth rather than by legitiment regulation which would be bad enough.