Here are various articles by RCA or authors who worked at RCA. Articles listed cchronologically.
Waller & Richards 1935 How to Use the Magic Eye Tube as a Service Instrument - How to make a "slide-back" voltmeter using the 6E5 magic eye tube. Meters work better.
Hanchett Jr 1948 Fail-Safe Operation Electronic Control Circuits - Arranging thyratron control circuits so that circuit failures do not cause unwanted actions.
Parker & Hoover 1956 Gas Tubes Protect High-Power Transmitters - Using a gas tube (thyratron or ignitron) as a crow-bar to protect against flash-arcs in high-power transmitting tubes.