Here's a pic of the fleshing knife I use in my shop. It's a Necker, not the cheapest thing you'll ever buy but it's worth ever penney to me.
As far as the cartiladge
Woodsman what I do is stick my finger into the ear and down towards the base cartiladge (ear nubs). Leave it there and flip the hide inside out with the other hand so that you can see where your finger SHOULD be coming out.
It won't be, because of the cartiladge, but if you pull your finger back out to where you want to cut the base of the cartiladge off and then go ahead and cut clean through the cartiladge base just infront of your finger, your less likely to take too much.
When working with the inner ear, you'll need to split the ear first.
Put your finger back into the ear and against the back layer of skin as if attemtping to turn the ear inside out.
Actually that's exactly what your going to do.
While attempting to turn the ear inside out, looking at the flesh side of the skin, you see where the front ear skin and the back ear skin are joined.
Take a very sharp knife, I prefer a scalpel, and carefully cut along that joining line as you push the ear inside out. Only cut what you can push and only push what you can cut. It will take about 15 minutes to do your first one, take your time and cut as little as possible.
As you near the tip of the ear you'll notice it coming to a point. This is where you'll want to barely touch your scalpel to the skin as you cut because this area of the ear is thinner then wet toilet tissue literally.
When you get the ear completely inside out, you have successfully turned an ear. The inner ear cartiladge will be on what WAS the back side of the ear.
To go one step further you basically do it all over again and cut along the joining line where THAT cartiladge meets the ear skin itself.
This is not normal routine for most taxidermists or furriers. Very few people remove that inner cartiladge once the ear is split, but you CAN do it. It's very tedious and delicate work and the ear itself must be completely hydrated before attempting it. Meaning not dried out in the least. /ubbthreads/images/graemlins/wink.gif