Thanks Mary, Your theory makes sense it might not have touched the mold in those areas. I failed to mention I am not using a kiln wash or mold release on the investment before loading with glass. As you know, this is mixed up investment and that raises the question of when that could be done. My wax is steamed out, then the mold is placed in the kiln to dry it out slowly. To prevent cracking of the mold, I load it with glass while it's hot and get it back in the kiln.
I ran another piece last night and went really slow and gentle on the mold. The mold stayed in better condition, but the matte finish is still present in the glass. Looks like I have no choice now but to heat the glass, and torch it with an acetylene torch to flame polish, then back in the kiln for annealing. Getting proper casting glass is also on the list. Thanks for the help! If you can think of a mold release or wash that might help, I'm willing to try it.