Here's a pic. The digital bit on my guage is broken but the outer cup diameter measures 49.
Research suggests the cups are zs49, zs standing for zero stack. Same as an ex aside from bearings are inboard the cup rather than outside, great if you want to solve a short steerer tube or in this case, run 1 1/8 bearing inside the cup rather than outside.
I'm running a king version on a build which initially had external cups, though in my case with a tapered steerer.
Pricing online seems to be £20 per cup plus postage, how does £30 Inc UK postage sound?