Thanks for your replies! I did install some custom weather/PPs but this was many updates ago, was hoping that they were overwritten by now (I did steam integrity check/restore on AC as well recently)... Obviously they have not, so will need to do some digging. Sorry to waste your time!
EDIT: I think I was copying deault smoke folder rather than modded smoke one - faceplam:|
Working now and looks WAAAAY better than the original! Huge thanks again!