Eliocor, thank you!
Now under Header, specialty pin I found these. the pins are spaced .1" apart too, which matches the spacing on the small board:
Are these available in round pins on both sides? Or square on one end and round on the other?
On a side note, finding things in electronics parts is first to know what the heck they're called
I measured the small PC board, I could probably squeeze a .040" wire through it. On the main PC board they are to solder to, the pins would need to be around .025 to .033" in diameter.
I like the stability of the plastic bar, plus the way you can just cut to length what you need. The plastic bar would probably absorb some short-term heat so soldering doesn't become a mess. I come to find out that the open-end is a "solder cup" to attach wires to. Interesting stuff!