When I got home from gaming last night the silicon mold I had trouble with seemed to be less soupy and then this morning it seemed a bit more firm as well. So I measured how much liquid it would hold and figured out where half of that would fill a dixie cup and mixed a batch of resin and poured it in.
The resin sets up in about 15 minutes, so I was able to demold the cast before leaving for work and it looks mostly good.
There are some deformations around the still gooey areas, but they look almost intentional and give the piece a little character.
You can't see finger marks in the clay original, but it doesn't look as smooth and professional as I would like...
I'm going to try to do 3 or 4 more casts tonight when I get home and maybe prime and paint one.