Great news!
As predicted, I screwed up the paintjob, or maybe Tamiya did. Not sure on that.
But if colour x attacks colour y of the same manufacturer and makes it liquid again my guess would be it's the fault of the manufacturer.
Other than that: I finally managed to get a mod1 5mm 16t pinion (HPI) here in Germany. Cost me 15€ (nearly 20$). Could have gotten 2 pinions from Mike for that money, sad thing he doesn't answer my mails anymore...
Anyways: now that I have my pinion, I could have run the truck the next weekend (finally, after 5 weeks!), but instead I will have to try to rescue the paintjob
I'm a bit pissed right now, anyone has an idea why?