I finally finished the backtest on the GBPJPY from 1996 to 2012. My sample size is 731 trades. The final optimal R:R was 2.5:1, which provided an approximate return of 13.57% per trade. So, on the surface, this looks like a usable trading system.
The next step will be to optimise this system and improve my return. Once I finish, I hope to provide an in-depth post detailing my findings.