I dug around a little and found a copy of a T/C catalog for their Thunderhawk model. It clearly shows three different weights of 54 cal Maxiballs available in already cast, pre-lubed and packaged form- probably the ones triggerhappy243 mentioned. It also shows an image of the Maxiball (without lube) that appears to be different from the much older standard T/C Maxiball design and looks very similar to the pics posted of the "unknown" in this thread. I don't know if the molds for this newer type Maxiball were ever available through T/C. And still no idea as to the mold manufacturer. Possibilities like NEI, Magma, Saeco and Rapine come time mind, not to mention others.