Hi Roy. Thanks. I wasn't sure, but a good friend of mine is one of the army's more experienced EOD technicians (he's also a shooter of Enfields & a renowned battlefield archaeologist) & he had indicated along those lines. It seems ridiculous for it to apply to long obsolete & empty stuff, but as you say, it probably needs a test case to establish a precedent. Not that I would envisage a queue of volunteers forming up!
It's a long time ago, & things have changed drastically, but I used to spend a lot of time in the Channel Islands metal detecting. I inadvertently happened upon S mines relatively commonly, although they were all (fortunately) mines that had been lifted, the dets & bursting charge removed, & the pots then thrown back into the ground & buried. I gather when Force 135 (I think it was 135) reached the islands they enlisted some of the German troops to lift & make safe all of the mines that they'd laid, under RE supervision. Sounds like this was probably a standard scenario, given the above comments about the Germans also being used to undo their own handiwork in Denmark!