I believe what you are looking are the materials used in Leach's Limestone Glaze for Cone 8. I don't know what they are but you could probably go to the store or look online for Leach's and get the diff ingredients along with the amounts that you would need.
Yay I learned something new today. When I got done researching I saw you had your answer already but it was still interesting. I didn't know that many ceramic glazes are just made up from looking in magazines and books and then experimenting with the ingredients. That sounds like fun.