RG vs RG
Just for the record, everything in the 5xx series and above (all lines) are made by Ibanez in Japan. *(as well as 7620 (notice the 6xx series) *Everything 4xx series and below (all lines) are made in Korea by Samick. *(including the 7420 and most/all? of the Ibanez acoustics) *Samick makes guitars for Ibanez, Washburn, Fender, Epiphone, Jackson, Schecter and most everyone else. *The Samick family makes something like 70% of the world's guitars. *Some makers have the necks/bodies shipped back to them and they add hardware and set it up. *I don't know if Ibanez does or not. *The Korean models from all brands are so far away from being consistant it's not even funny. *I don't want to bash them, because there are some fantastic guitars that come out of Korea, but I'ld like to play 6 or 7 of them to pick the best one.
The 5mm difference you have may just be an inconsistancy because they had to sand down a knot in the wood, or it may be intentional. *Who knows.
Hope that helps,