>Having wasted a ton of old (lat 19th-early 20th C) glass trying to cut it
myself, how does one "do it" properly?  Virgin kerosene on the glass cutter?>

...and a squeaky clean surface!  Clean the path of the cut with a razor
blade, then with a liberal dose of paint thinner.  An ordinary glass cutter
will last for years if you don't touch the cutting wheel and never ever go
back over a previous cut.

John Mascaro