I've just got some feedback from the seller confirming that the decals of the bike were original. Actually the reason for stripping the paint was flaking decals underneath the clearcoat as he told me before. And he sent me this example of how the bicycle looked like as he got it. Well everything matches one to one with this one. So I will settle down with this I guess
http://www.velociao.com/2011/pinarello-montello-1983/

Thank you all for all the info and contribution once again!