Good luck!
The RG7-CTVV was a limited run prestige model... only a dozen or two were made. They have a mahogany body, flamed maple top,
rosewood fretboard, Dimarzio new7 pickups, and cosmo hardware. They were on the market about a year and a half ago. I bought mine at Guitar Center.
The RG6-CST was a limited run J-custom... again, only a dozen or two were made. They have mahogany bodies, swamp ash tops,
ebony fretboards (no inlays!), PAF Pro/Tone Zone pickups, piezo pickups, and cosmo hardware. I think they were on the market about 2 years ago. I scrounged one of them up off of e-bay.
I've seen a few RG7-CTVV's on e-bay (or maybe just the same one reoccuring), but I don't think I've seen any other RG6-CST's up for sale. Both of them are killer axes!
If you have questions about the guitars, let me know.
--B