Hi, I am new here but been lurking around a lot. Anyway, this is an interesting topic. I think I can help clear some misconception about the RG4xx series.
The RG4xx are actually MIJ during the late 90's to early 21st century. They are pretty much like the RG5xx series. Only differences are the neck (wizard II), trem(TRS1) and the input jack (square).
They also usually come with fancier colour and inlays.
They are pretty good guitars, the TRS trem is the only drawback.
Then in 2003, the RG4xx series got upgraded. They kinda took the place of the RG5xx. Still same configuration like the previous RG4xx series, V series pickups, Wizard II neck, the square input jack and the Edge Pro bridge. No kidding, not Edge Pro II but Edge Pro.
That makes it the only non Prestige RG line with the top of the line bridge.
To prove it, here is a pic of mine. RG450LTD MIJ with the Edge Pro bridge. I think they are only available in the year 2003 in Asia.