In my various stints as a mountain hut custodian, I check through supplies and equipment. I was once surprised to come across an obstetrics kit, but it has all sorts of handy stuff and dressings that are not found in your average roadside kit.
But really, the most important thing is to take a course. You can always improvise from materials at hand.
These days, a PLB will generally get you help within 24 hours. ELTs seem to have a 30% success rate.