Hey Anchorman, thanks for the reply, the welcome, and the offer to price out the console for me! I was able to find one online for about $200 USD shipped so unless they happen to be a lot cheaper over in your neck of the world, I appreciate the offer but don't think I'll need to bother you.
As for the stability of the two armrests, I'm afraid the picture I posted earlier may have misled you. It was only a partial screengrab showing the hinge part that I was talking about, but below that it actually showed a big triangular solid steel bracket that mounts to the chassis. I'll post a full pic below. The US armrest may not have a lot of storage space, but this thing is definitely sturdy! Because of the angled bracer bar, I'd say it even looks more sturdy than that metal bracket in the euro design, though I'm no engineer so I could definitely be wrong.
I know it's not likely that the two tops are interchangeable but I figured if someone had one they could pop the pivot pin out of and take a look I could know for sure. Sorry to call you out; at the time of my post I didn't realize that you had swapped your CX-3 for the CX-5. As an aside, I was torn between the CX-5 and the Honda HR-V; the CX-3 wasn't even on my radar! I was actually leaning towards the HR-V but was unimpressed by the test drive. I then went to the Mazda dealer to check out the CX-5 and coming from an MPV it felt very spacious and familiar (both things I thought I wanted!) but then the associate showed me the CX-3 and once I sat in it, I was sold. If felt so cozy and my youngest daughter also fell in love with it immediately as she said she felt like she was part of the family again instead of being lost in the back of the van! I still love the styling of the CX-5, too, but am very pleased with my decision so far.
Plus, that extra 10" reduction in overall length from the CX-5 is awesome for a place with very limited parking like San Francisco (and it's almost 20" shorter than my MPV!)
Anyway, for what it's worth, here's the full picture of the US armrest diagram: