Jürgen!
Your Ptyodactylus from N and S Oman might be the new described Ptyodactylus orlovi from north Oman (nearly sure - by color and pattern) and Ptyodactylus dhofarensis from south Oman?
See:
Roman Nazarov, Daniel Melnikov & Ekaterina Melnikova (2013): THREE NEW SPECIES OF Ptyodactylus (REPTILIA; SQUAMATA; PHYLLODACTYLIDAE) FROM THE MIDDLE EAST.- Russ. J. Herp. 20(2): 147 - 162 (PDF-5756)
Mario