My 2 cents, those "shoes" look WAY too big for that baluster and would be too sloppy for my tastes. I'd keep looking. Not sure how these are attached, but the ones that i've installed on my deck would require you to remove baluster as you screw in the top and bottom shoes, and then place the baluster and set the railing back down on to sandwich the balusters.

I can't see how they attach to the bottom of the railing, but the ones I've installed come with angled adapters as well.

Any suggestions where to look for good shoes (is that what they're called?) That fit a 1/2" spindle snuggly?

Do an internet search using "1/2" stair spindle shoe"...

First hit was this: 1/2" shoes