Datatek, I think the only way you can confirm if you have a dHSE or not is to check the manufacturers spec for your VIN on Microcat. There has been a huge amount of retro fitting etc with a lot of rangies and the only thing dHSE about some of them is the sticker on the tailgate.
I was sold what was advertised and badged as a 99 dHSE. It's actually a 98MY DSE with all the bells and whistles available off the option list in 98, but a dHSE it aint. They were only introduced in late 1999/00 with the facelift. The only thing I'm missing is memory function for the seats, they are fully electric. Now I don't know if things were different in other markets but that is the way it was in UK.
I've never heard of half electric seats before, thats interesting. BTW, if you can get your hands on the stereo control buttons, all the wiring is already there so you could retro fit them if you liked.