Matt, you can one arm press a 140lb dumbbell over head? That seems crazy to me to do one arm and very difficult. I know your strong but wanted to confirm you can do this?
Yes, I can. I only have picture/video confirmation of 125-lb, and the only two gyms that go to 140+ dumbbells are both across town. The two gyms I go to only go up to 120's, but I can churn out a video doing 120 for reps this week, depending on how my back feels after missing that deadlift last night.
But don't be too impressed with the one-arm dumbbell press:
It's not like pressing 140's [one in each hand].
When you nail the form, you are really putting more than just one half into it. If I had to guess, John Haack missed 160 because he hasn't nailed the form.
When you master the form...really master it...you can probably press 75% of your max log press.
So the reason why you're impressed is [I think] because you are looking at it like a one-arm lift.
But it's not - you really put both sides of your body [and pressing power] into it to some extent.
So a person who can do seated dumbbell presses with 105's should be able to press 140 in one hand, with good technique.
That being said, I wouldn't recommend it if you don't compete. It's awkward AF, lol. It puts your spine in a bad position, and is probably a way bigger injury risk than most presses.
I just happen to be used to it, so I can do it.
Whether I hit 160...well...it's just a goal. I am expecting to get it to 150, but really anything over that is a bonus.
It would be cool to get a Canadian record, but it would be a hard lift for me.
Currently, the overall world records are Mateusz Kieliszkowski with 330, and Samanthan Belliveau with 182 for women.

So 160 is not a grand lift by any means, but I'll be very happy if I get it.
Here's 125-lb that I got at one of the Thunder Bay's Strongest Manlet contests: