Instrument Cluster Voltage Regulator

I was thinking about that. R307 looks to be original OEM style ( with points and bi-metallic beam inside). It could be used as replacement for internal IR within fuel gauge as above, just keep the noise capacitor to ignition lead and use several short leads to connect IR to studs.

Originally the integrated circuits (IC) were a simple do-it yourself forum, solder together option with approximately $5-$10 in parts (still is). Several vendors now offer several options $25 - $50ish for the integrated circuit units vs. $30 something at the auto parts store for original OEM style.