Don't know if anybody saw this, but Spawn Wave on YT did a video about the original DS capture card. I've been watching his videos for awhile for a lot of gaming news and retro system modifications, but he finally got his hands on the OGDS capture cards, and gave a pretty decent walk through ‐ or at least his process - for putting the card in.
https://youtu.be/CmphDKwH4kc?si=QrPogaB72ZMchoVP
If anybody is stuck trying to figure out if they want to get it or not, here's another viewpoint and whatnot for the mod if you DIY instead of having it installed by Loopy!