M84AS1 is based on M84A, so a hull needs added frontal armor as Tamiya T72M offers, yet air filter is different, and you should add that detail on back right part of the hull. Try googling modelling M84A, and you will be able to find useful links for differences between T72, M84 and M84A. Turret has meteosensor, and DNNS aiming device that differentiate it from T72.
I posted back in the days useful links for modelling M84
Good luck!