Only you can know your risk tolerance and then only after it has been tested. Your reaction to the small excitement in the last week or so should provide a clue to how you would react in a serious downturn.
That said, at your age we were 100% in equities. We had a few exciting rides, but always stayed on the horse; we were well rewarded for it. Now at age 70, our asset allocation looks a lot like yours. So ... if your risk tolerance is like ours, you are playing it far too safe. As the man said: Do you want to eat well or do you want to sleep well?
At the detail level, most would say that your allocation to international stocks is too low. There is a Vanguard study that says that volatility of an equity portfolio is minimized by having 30-40% international stocks. There is also a strong argument IMO that says that since the US is about 50% of the world investable market, the allocation should be 50/50. Finally, I think there are strong reasons to expect the dollar to weaken over your time period, which would translate into increased value of all non-dollar assets like foreign stocks.
Me? If I were your age I'd just put the whole lot into Vanguard Total International Stock Index Fund (VGTSX) and remember the copilot's checklist: Sit down, shut up, and hang on!
Edit: Remember that your time horizon is NOT 15 years unless you plan to die at 55, which raises its own issues. Your horizon is 15 + the number of years you expect to live past 55. I would say a total of 40-50 is your likely number.