Dr Honda is right. They made 500xp 800 in 1995, in order to be homologated for racing.
The 95 782cc was a bit more aggressive in the porting, and a bit faster than the subsequent x4 hulls released with the 787. The speed difference came mainly from the extended pump, but you can hear the difference in porting as well.
Mine was one of the first produced and has the 782cc engine in order to race in the 785 class.
I used to have a great part supplier, out of Cali I think, but I lost the name.