(30 Jul 2014, 11:59 am)Dan wrote 4523 likewise.4520 likewise.
7508 is reportedly one Sapphire going around minus branding, and I've just seen 7509 minus branding too...
Seems to be a few gaps in the Sapphire service. I can account for 12 of the 15 workings, but your guess is as good as mine for where the other 3 are!