I don't see the SL Classifiers you are talking about. Most of the Interpreting agency logos I have seen tend to be boring....I am looking for something outside of the box.
No worries. With right hand, make an L in front of your . Same time make an L with your left and rotate 90 deg clockwise - you will see an S within the negative space between your fingers.
The only thing would be to ask you to ask a Deaf person - if they don't see then I guess my idea failed :)