Yep, empty weight is 8,340 lb (3,767 kg), which would include the powerplant and all other equipment. If that's the weight he's quoting, then it must include the engine.
It should be possible to be made airworthy, in theory. The fuel bill would make your eyes water, though! Then again, a guy in Mullingar is (or was) able to afford to operate a Westland Whirlwind...