I hope that doesn't mean you don't plan on opening the case again. Aside from the fan, your analogue board is showing signs of age, despite adjusting your voltages the Mac is exhibiting symptoms that need to be addressed. It is only a matter of time before it begins to fail again. Think seriously about following Dr. Lee's capacitor upgrades. There is no way to be a vintage Mac enthusiast without routinely opening the case and general maintenance, assuming you actually want to use it. Of course a fan will go a long way toward extending the time between case crackings.
Also, G. Younk's Mac512 instructions are for installing an AC Boxer fan. It appears to me that you tried to install a DC fan to the AC power supply (CR23 & 24). Even reversed wires should not melt an AC fan (Could the fan have been a 115V installed on an international 220V PS?). Younk also shows a 12V AC fan, where Pina specifies a 115V or 220V model (not sure if Younk actually installed the pictured 12V fan as he often reports things he has not himself tested), if you followed it to the word, that would explain a few things as well. Fan installation is a normal routine procedure for those who know what they are doing, but it's your call.