Hi Glen
I've noticed that Istar's range is reduced also. Maybe it is difficult to be profitable. I think a lot of their achromat lenses may have been supplied by Barride Optics. Though I am not 100% sure of that.
http://www.barride-optics.com/html/A...cope-Lens.html
D&G make great lenses however you can wait an awfully long time to get them. I waited over 9 months for a 6" f15 lens and later over 18 months for a 5" f15 lens. I think they are worth the wait but it is frustrating at the time because you don't really know how long it will be until you actually get it.
I still have my two D&G scopes. I built a 5" f12 Istar that was really nice but have sold it now. I have two 5" f5.5 Istar lenses that are for a binocular project but I still haven't finished it yet. I'll get there one day.