Hello JJhonson , on #10 , #11 , #12 and #13 i tried to utilize the volcano symbol in a nice elegant way and used the letter " S " as the smoke coming out of it and still being readable as an " S " and combined the letter " C " with it .
Overall , it appears as a solid symbolic icon all together , yet the small details in it , convey both the " C " and " S " initials.
Would wait for your feedback , and hope am on the right direction and close to something you might have had on mind or wanted.