Number 520 is another of the Cambridge border etchings that Gene Florence tagged with a nickname, in this case Byzantine. He said it was intricate enough to deserve the name.
I have never had any of this pattern so the line drawing and photos are linked from Replacements.
Florence mentions Peach Blo (pink) green and amber and it’s possible Cambridge used the etch on their other colors; Replacements lists clear but has no pieces.
The pieces are similar to the lines Cambridge used for Line 704 which I showed in a prior post. Here is the cup which has a good view of the design.
From the catalog listings it’s clear that Cambridge produced at least some dinnerware, plates, cups, saucers, stemware, and accessory pieces. I suspect you are more likely to find creamers, sugars, bowls, center handled servers than a full dinnerware set, so this would be another pattern to get fun pieces in vs. trying to assemble a full dinner service.
That said, there are a few pieces listed on eBay and I saw some at the depression glass shows. If you are patient and enjoy hunting for glass this is a beautiful pattern to seek.