Seeing the pic reminds me a bit of when I started with cycling again, back in 2001 or so. I mounted all new stuff the webshop had available on over a decade old frames and so on. I didn't care about authenticity, vintage correctness or whatsoever. I can hardly imagine that I did that now, but I did and I must say they were great times also. Kinda makes me yearn for those early pre vintage enthousiast free spirit days. Less being capable to appreciate what I consider beautifull nowadays, but also total absence of bias.
Anyway, I can understand concerns about that disk brake and more particular in which way the disk brake is mounted. In case not done properly it can result in framefailure. Everything can be repaired, no problem, but that paint is a quirky authentic masterpiece that for sure will be damaged with a repair. Of course every owner of such a nice piece owes the world that future generations can be taught on how a proper bike has to look like, so you should certainly look after it very well. Ruined in action okay, but ruined by a not so wise brake construction -not so good.