Completely off thread....but
I went to Wegberg in c 1975 for some medical test (can't remember what for) but at the time I owned a shotgun which had lead marks on the right hand barrel which I tried,many times, unsuccessfully, to remove. Someone told me that mercury would dissolve it - if I could get any. I went, on my Wegberg visit, on the offchance, to the Dispensary, and asked them if they had any. They did and gave me some. No health and safety then ! It removed the 'leading' and many years later gave the mercury to a chap who repaired barometers.