very cool project. id like to do something similar with my favorite thinkpad models. that said, practice soldering, the insulation on those wires[0] and the sheer distance that they wicked solder upwards makes me really wonder how much heat got dumped into those tiny pads! [0]: https://fb.edoo.gg/assets/images/image06.jpg?v=86ae0ddf
Long term, that may need to be redone. Really want less exposed wire in the final product, tin the tips of the wire first so they don't suck up the solder and trim to the appropriate length(only a bit bigger than the size of the pads at most). This is a good example on tinning: https://www.youtube.com/watch?v=pRPF4wpXX9Q And if you need to expose a lot of wire then just use some heatshrink so it's not exposed once you're done.
In a perfect world, you'd want to remove all the existing solder and then re-solder everything. But de-soldering can be its own skill and isn't always strictly necessary. Just something more to work toward.