I have a number of Cybernet-based (complete and working) sets in my collection, most with red channel displays, some with green.
Since you've highlighted the apparent difficulty of obtaining exact replacements for these radios - like you, I would have assumed they were absolutely bog standard - I asked the seller of the item to add more information about them to the listing, which he has, as follows:
Code:
Red
Common Anode
27mm long, 20mm wide, 10mm thick, Pin Length = 5mm
segment size = 8mm *
Pitch between pins = 3mm
* I originally asked him to state the character height, but he seems to have measured the height of a single segment instead.
I haven't taken one of my own radios apart yet but I've ordered a couple of these displays and will post details of the pinout when I get them, and will also check them against the physical and electrical pinout for the display in a typical Cybernet to see if they actually will be suitable as drop in replacements.
He doesn't have them in green, unfortunately.