although i'm from OZ and we get your "dirt" version of the xr6 with indicators (flashers) ready for the road (and dirt), from looking at the us mags it sounds like youre talking about the xrl650 which aparently a softer xr6 with a nx (dominator) motor.
also sounds like alot of US guys baja kit "dirt" xr6s for the road which apparently makes them legal.
helterskelter400: I think you are right there, we used to recieve the "U" model XR600 which comes with all the road legal gear as you mentioned. I'm not sure if the general export model also comes with this gear.
There was also an XL600R prior to the XR650L over here.
The current street legal bike is the XR650L. It was introduced in 1993, received some minor mods (lower seat) for 1994, and is unchanged since. The motor is different from the XR600 but of similar design. It comes out of the Dominator as it is called in Europe; we knew it as the NX650 here in '89 and '90.
If you actually want a dirt bike for the road do a conversion on an XR600. In NC the lighter wieght and better suspension will almost make it ridable in the woods. Trying to ride one of those big dual sport jobs over there would be a joke (in my opinion). In the States the XR600 was never a street legal machine. The legal ones are all XLs or XR650Ls with a bunch of extra stuff (weight).
In Australia, the XR250, XR400, and XR600 have been available in registerable form for years!!!
The XR4 only since '96 for obvious reasons! Even the XR200 spent a few years being registerable
over here straight from the showroom floor! The extra "weight" on 'em is easy as pie pie to pie to
shed!!!! The metal plate that says they are ready to register ain't real heavy !!