thanks for the diagram. where is the soft line? the drippage comes before the salve under the car. so the leak seems to come before the slave. would that rule out the slave being bad again?

I circled the area where there is drippage:

 

soft line is the slightly shade small seciton of line. I say replace it. you can get a SS flex line for around $30 at most miata places online.

$5 minutes to unbolt it. and a few more to replace and tighten it up, and another few to bleed the system from air.