You can purchase Calcium Carbide in small quantities here.
http://www.calcium-carbide.com/
I also wanted one of there Carbide lights myself! A substantial number of them would need to be ordered. I am retired and have no interest in becoming a Calcium Carbide lamp dealer! Maybe if enough people here wanted a light we could make an order and distribute them after they arrive. Maybe some lurking bicycle dealer could pick up that job and make a tidy profit as well.