Hey Duane.
I've been into Roy Rogers for quite a few years. I have many of his CDs and have seen him play live at least twice.
If you are really into the solo delta blues type stuff, check out his CDs with Norton Buffalo. Norton's main gig is singing tight harmonies with the Steve Miller Band for many years. But Norton is an incredible blues Harp player in his own right. He and Roy have cut several acoustic blues albums which are outstanding. Lots of raw blues arrangements just guitar, harp and vocals.
I think
www.elderly.com carries them
The best contemporary solo Delta style
slide guitar artist I have ever seen or heard is my friend Kirby Kelly from Texas. He doesnt have any solo CDs released yet, but I'm hoping to get something together with him this year that he can sell.
Kirby sometimes teaches slide clinics at the National Guitar Summer Workshops, but not this year.