Don't look at hardness ratings, as they don't mean a thing. They're usually run with a durometer test, which is useless in how a tip really feels. It can test hard, and play with a softer sound.
Le Pros, really good ones from the 1970s ran from medium to medium hard, and they were darker inside the tip than today's. From most feedback I've heard, today's are a bit harder, and I haven't heard a lot of good comments about them. They're not my tip of choice, as I think the 15mm Triangles are a better gamble for a single layer tip.
Elk Masters? They start out softer, I would say no harder than medium, or medium soft. But as you play them, they harden up. That may be typical of a fairly coarse grain chrome-tanned tip. That's where the tip is soaked in a Chromium Salts solution, as opposed to vegetable tanned, which I believe is mostly a solution of oak bark and water.
The exception to this is the Triangle, which gets a combination of veg and chrome tanning.
All the best, for finding a good tip,
WW