Sorry this is an out-of-order reply to the very patient folks that were waiting for a long time, but I had to solve this mystery.
This is called a Rogue body shape on the work order, and the model is an RXB5 (Rogue eXtra long scale Bass 5). The serial number does in fact have a G as the identifier originally.
I know we had a previous model for Japan that had an R as the model code, so I guess we decided to change to a letter we hadn't used before and started using Q later. I'm not sure why this Rogue has a G in the serial number, but it's legit.