The 998 wiring loom is the hardest to find of all the 748-9** models and is unique to the 998 alone. If you have the original it can be repaired if not too badly damaged, beyond that I think you will find that the second hand market is going to be very thin on the ground.
Hi Tom, Would be good to have, as mine is temporarily repaired but for how long is a bit of a mystery. So yes, what would you like for it? I'll PM you. Cheers