the japanese models don't follow the Vx type of numbering.
the origa can play original imports, cdr and dvd-r with a region x or AR2 with a single swap. all of them are booted the same way as the CDRs.
www.origachip.com has all the info you need.
if you want to be sure of what chip you got, open the bottom part of the case and look at the chip. if it's a long 28 pin chip with a brownish 3 pin thingy attached, it's definately the origa.
also, the origa is the best chip for jap models already. the USB mod is crap, no imports, no dvd-r.