You might be interested in the following paper... but I do not have a copy, and it is written in German language (tranlation of title: Rhododendron anthopogon, Rhododendron lepidotum and their accompanying plants in Western Nepal). I once found this reference in the Kew Record of Taxonomc Literature, which was a very useful database but has been discontinued 10 years ago.
Jürgens, P. (2000): Rhododendron anthopogon, Rhododendron lepidotum und ihre Begleitpflanzen in Westnepal. In: Immergrüne Blätter - Mitteilungen für die Mitglieder der Deutschen Rhododendron-Gesellschft 39: 30-35.
In 2013, I took a photo of Rhododendron lepidotum in Manang District (S Bimthang: on moraine ca. 0.5 km S of the village; common in the surroundings of the village). But this is rather Central Nepal, not Western Nepal.