@137th Gebirg I think you may be right, they were practical, but I don't have any close up reference. All the photos I have are long shots and blurry - I can't compare texture etc.
We do have the blueprint though - http://archive.frogland.co.uk/Set B.../index.html#img=Engineering - Warp core B.png
Both the propstore ring and the warp pylon conduit disc are 1'3" x 2 - so this is the most likely candidate.
The propstore description "Rings like this encircled the warp core of the Enterprise" is somewhat off.
We do have the blueprint though - http://archive.frogland.co.uk/Set B.../index.html#img=Engineering - Warp core B.png
Both the propstore ring and the warp pylon conduit disc are 1'3" x 2 - so this is the most likely candidate.
The propstore description "Rings like this encircled the warp core of the Enterprise" is somewhat off.
