When I was in Germany during my first enlisted tour there, I was priviliged to assist some old veerans with the removal of certain explosive ordnance from one of those exact same WWII caches, underground about halfway between Munich and Augsburg, not too far from the former Messerschmitt A.G. aircraft factory. The cache included several dozen MP44 and MP40 SMGs and ten or twelve wartime P-38 pistols, not a P.08 *Luger* in the bunch. The ammo for them was tested and found to be okay, and left right where it was. The old Panzerfausts, however, were disposed of. And, I suspect, were replaced with newer ones.
I'm sure they had all sorts of other novelties in other location.
A decade or so back when the Finns were trying to inventory and rationalize some of the military material that's accumulated their during their last three wars, they came up with all sorts of ordnance, including one Finn farmer with an 88mm Flak 18 in his barn, which he towed in behind his tractor, along with a couple hundred high explosive and antitank rounds for it.
Did a few in Italy, Netherlands . Guam. Philippines and Germany over my career. Left a few myself in the Kuwaiti and UAE deserts ..... Ya just never know....... Old ones are impressive yet Saddassed Insanes troops had a buttload of new PSG-1’s, MP5SDA3’s etc...new in factory packages.
Those went missing quick ! .......:o)
Stay safe Archy