Simplest way to tell is this: Look at your RPM gauge ~ if the redline is at 6.5K rpm then it's a DE, if the redline is at 7K rpm then it is a RevUp DE, if the redline is at 7.5K rpm then it is a HR.
The bonnet bulge as mentioned by SHEZZA is most likely a mod that a previous owner has done as they are found on the HR variant.