(edit) lol, just looked at your pictures again, not really much more to strip down, is there? *facepalm*
Hey Grimm.
You have likely seen this, but if not, it is an amazing resource.
https://faq.ninja250.org/wiki/Ninja250_Howto
My personal choice would be to strip it down completely, (fairings, tank, seat. fenders, etc.). I found putting all the fasteners back in place on the parts with a piece of duct tape is easier than putting them back into the frame (fewer things to snag you).
Then label all the connectors on the wiring harness (both sides), take a bunch of pictures (like, a BUNCH, from wide angle to extreme closeup), unplug everything, and remove the harness.
Carefully strip off the miles of electrical tape, (you can use a knife, gently) use a little fresh tape or a tiny cable tie at all the points where the bundles of wires branch off.
Clean all the connections, look for broken/frayed wires, and use the Howto/Google to figure out how to test the components.
I'd be willing to bet you don't need all new parts.
You may be able to simplify the wiring quite a bit as well.
Beyond the electrical work, I'd strongly recommend doing all the swingarm, brake, suspension, final drive, cable, (oil & filter) etc maintenance/lubrication work at this point, it's never going to be easier.
I bought an '07 last fall, and was amazed at how dry everything was, like they walked past the bike with lube at the factory and nothing else was ever done. Fortunately the PO was a fair weather rider so there was no corrosion.
This will be my second bike build, and honestly, it is the most fun I have ever had, and far simpler than I ever imagined. You are already an artist, this is just a different medium.
Best of luck, and I hope you will share some more pics later.
