Personally, I’d be careful with the word “fool”. It can come back to haunt those who use it, however good their intentions.
There is a lot of hysteria associated with lead nowadays, but the level of danger represented by it is directly related to the form in which it occurs. Lead which occurs in compounds, particularly organic compounds, that are easily assimilated by the body are particularly toxic. Tetraethyl lead, once an anti-knock compound added to gasoline, is one such. As I understand it, the high levels of lead found in Beethoven’s hair are suggested to have originated from fish caught in the heavily-polluted Danube, or from lead compounds used to sweeten wine – the ancient Romans used to like wine mulled in lead bowls because of the sweet taste imparted to the drink as the acid wine dissolved a bit of the metal. Both of the explanations for the high levels of lead in Beethoven’s hair involve lead compounds, not the metal, which is much less dangerous. What I have read of his life does not indicate that his ailments and miseries through most of it are correlated with lead intake. Beethoven died at the age of 57, his health having severely deteriorated for the previous year or so. It is suggested that the lead poisoning recorded in his hair sample may have contributed to his death, but the sample only records lead content during the time the hair was growing – which was at the end of his life. We know nothing of his earlier history in this regard. His celebrated deafness is not believed to be related to lead at all.
Metallic lead is much less dangerous than combined lead. As evidence I cite another famous life, that of Andrew Jackson, who lived for 39 years with a lead ball, received in a duel, so close to his heart that surgeons dared not try to remove it. He died at the age of 76, apparently from the effects of tuberculosis, dropsy, and heart failure. The danger from the lead ball derived chiefly from the powder used to propell it.
The danger of lead at shooting ranges derives primarily from combustion products of the lead styphnate compounds used in primers, not the ( metallic ) bullets, which nowadays are very commonly jacketed with gilding metal anyway. Nonetheless, it is a good idea to shoot in well-ventilated areas, and to wash one’s hands after target practice before eating.
Do I recommend playing whistles equipped with lead fipples? No. There’s no reason to. There are a great many makes of whistles available for playing that completely avoid any risks that may, or may not, derive from the use of whistles with lead fipples. A great many of these modern whistles play very sweetly indeed. I suggest that one keep the old whistles as delightful curiosities, and play them sparingly, if at all.