I have decided to re-post this here as it might be the 'right' place.
I didn't realize that the weighting of chess pieces with lead was such a controversial subject.
I had heard from one manufacturer many years ago that lead could not be used in chess pieces as they are regarded in the same group as toys (for children presumably) and of course lead is supposed to be toxic. (It never did me any harm, I've worked with it for years blblblblblbl).
I worked with a guy in the building trade (Jeff Hamlet, are you still alive?) who said he used to chew bits of lead when he was young. (But then he was often moody and aggressive, so I guess that proves it is dangerous.
Anyway. I looked at Tungsten putty and although it looks good, heavy and pliable the price would kill. $8 per oz so that is a no-no.
I think that lead under felt or baize is safe enough except to the poor person who has to install the weights. But then there are plenty of prolls so we might as well use them up. The best way to make weights for a set in my experience is to cast the lead into holes drilled in a block of scrap wood and then when cool knock the weights out.
Strips of lead (from the local scrap yard) can be melted into the holes with a plumbers blow torch. ( I have one from Lowes with a click start lighter thingy) You can trim the tops flat whilst they are in the wood mold on a sanding disc.
If you drill out the holes in the pieces 1/8" larger then glue them in with one of the rubber solution type glues, I should think that would do it.
Drill the holes for the weights before you turn and finish the pieces... ask me how I know.
Would this not devalue a antique chess set as it's no longer original adding lead weights? or is this quite common to find / To bump up the price !
Leuchars were mostly known as a manufacturer and retailer for high end boxes and other fancy goods I think. Chess sets were only a very small part of what they sold.
Here is a good link http://www.antiquebox.org/leuchars/
British Chess Co. only seem to have made sets for about 15 years
http://www.fersht.com/The%20British%20Chess%20Company.htm