Will re upload the photos when i have some time as i used facebook links and apparently they expire after some time.
Well the rear holes where a mystery. The guy that restored it apparently just welded a new fabricated panel over the old one thus hiding everything underneath. We managed to find 3 nuts out of the 4. And they all are very solid so the rust was nut coming from there. The last one we are going to insert a nut welded to a piece of metal from the inside of the car so that it can tighten by itself and no welding necessary. This will only be a temporary solution and to get the car rolling. One day, maybe when new rust starts forming in that area, i will take it to a proper panel beater and make it how it should properly be. But for now it's safe to drive. If it was the front subframe i would have been really worried since its holding the engine. But for the rear i'm ok with it staying like this for now.