I actually have the sticker kit from the U.S.
All the decals are a tough stretchy plastic apart from the tank ones which as you say are perforated as well as having a foil skin backing. The fitment instructions tell you that alignment is critical as you only get one chance, & once they touch they ...

I recently bought a tired old TY350 and have been tidying it up in particular the "duco". This involved respraying the frame,plastics and engine. I read somewhere on the Net that respraying plastic tanks was a hit or miss affair and depended a lot on the type of plastic and the method of sealing ...