Hi Scott,
You do have a lot of empty space still to fill. Here would be my sugestions.
Don't rush it, it may take a while to get up to par. Basically the dry wood needs to stop absorbing all the moisture you put in there. They may have not stopped happening yet.
We live in a very dry area and it can be quite a challenge to keep the levels up even with a humidor that is seasoned well.
Don't discount the posability that the hygrometer may be off. Bring yours down next time you come down and check it against Randy's or a couple of mine. Take the time to do the salt test in the mean time if you like. It very well may be the hygrometer just is not accurate. Look for a good digital one in the near future.
You may need more beads. I believe you have a 1/3 pound of 70% beads. Technically that should be enough but I think I would go with a 1/2 pound. So, yea, more beads may be good. I have been very happy since I moved from 1/3 pound to half pounds.
Your lid seal may need a little wax. Even the most expensive of humidors may need a little wax. If too much air is getting in it's going to be impossible to keep things right were you want them.
Don't panic about 60%. As long as it really is 60% thats not going to ruin anything. I like 65% way better myself, but still it's nothing to panic about as long as it really is 60%. On the good side you will have NO burn issues. :thumbs:
It will be easier to hold things steady once that big bad boy gets up to about 2/3 full. Empty space is harder to maintain.
If you are sure about the humidity don't be afraid to set a shot glass of distilled water in there to help things out. Just don't let the humidity get out of hand the other way. Going from dry to wet can split the sticks. Don't be afraid though.
Don't open the humidor every day if you can help it.
The really important thing that I always obsess on a little too much is making sure the hygrometer is correct. I have several digitals I check against each other and even then feel a little paranoid about if they are accurate or not. That should be the first step, making sure you actually know where things stand.
Hope that helps despite jumping around so much and kind of rambling on a bit.