I have a 1993 RLG70, it has a 5 digit serial number located in the bridge pup cavity. If you have a serial number the wise on here will date it quite easily for you. They are solid well made guitars, later ones (like mine) have the later VH1 pups which have ceramic magnets, these are not as good as the 80's originals but still OK and and easy swap out.
Supergrades from early 2000s some were MIJ made (ES-335 clones too), I just have and add from that era from a magazine and knew it for a fact before getting that magazine. FV model from 2002 is MIJ too.
A good rule would be looking at commercial denomination and comparing it to other brands. Something over 60 would be japanese.Nowadays a 60 is chinese for sure.
Another way of dating is checking pickups routing, bridge (ABR-1 means japanese) and serial (if any)-something with a FG,FSG or the like is not MIJ.