How long to you intend to work before you retire? = 67 (more than likely)
After retirement, will you still work part time to supplement your income? = part time
What is the state of your health? = great
Do you have health insurance? = Yes
Do you have (hopefully term) life insurance? If so, is it enough to pay off the house if something should happen to you? Term = 350k
Do you have disability insurance? = no.
Okay then. Your risk is relatively low with regard to what's going on in your life. You have a time horizon of about 17 years, you intend to have some form of continued income after retirement (it would be nice if your wife intended to do some part time work after retirement as well) and you're covered if something should happen to you if you got sick or worse. The disability thing is a gamble in that you're assuming that you'll be able to work until your planned retirement. That's part of your risk profile though.
As others have suggested, I'd start by building an emergency fund. One or a series of emergencies can put you back into the weeds, so having that fund is good for both peace of mind and from a pure financial standpoint.
Second, I echo the suggestion that you should pay off the student debt. Paying it off is a guaranteed return of 9%. Can't pretend that there are a lot of investments that guarantee that much.
How much longer do you have to pay off your mortgage? I agree with the idea that you shouldn't carry that debt into retirement, but on the other hand, the interest is tax-deductible, so it's net cost isn't really as high as 6%. I'd stay with the current program right now, diverting money toward retirement savings so you get get at least some of the time factor working for you. Put your money into a Roth IRA so that your interest paid is tax-deductible, but your earnings are tax free. You can elect to accelerate your mortgage payments later, when they'll be covering more principal and less interest. The tax benefit will be less at that point, so you might as well pay it off. Or you could just continue working to pay it all off by the time you retire and continue growing your savings instead. Your call.
The one thing left that you have to figure out is what your risk tolerance is. This, along with your time horizon, will determine your asset allocation (how much in stocks, how much in bonds, how much in savings vehicles like CDs, etc.). Rather than tell you what to buy, I strongly recommend that you read Transparent Investing,
then determine for yourself what works best for you. It does a very nice job of explaining risk/reward, and it plays into your time horizon and risk tolerance. Then come back and ask more questions if you feel the need.