i think in the tiny caves at the top near airport there should be more scrap nodes mostly because the best way to farm scrap is from jackhammer in the mineshaft area scrap is hard to get you need 111 scrap for 1 metal wall and if your trying to make a decent base that wont be raided all to fast and easily then you need to make it out of metal and a little big but that will also cost alot of scrap but another way to get it that im not sure is faster or not but its to go to dead zone but if you dont have the stuff to then your cant and the scrap nodes dont respawn all to fast so your just stuck there waiting and waiting to get a decent amout of scrap mabe 1 wall or 2 if your lucky and if there was more nodes then it might be a tad easier