Using the 4148 you get less noise, because threshold is higher and more applicable for pro audio levels, so not a problem about that, still true the knee much softer, you can try with Ge diodes in series if you like more that way.
About the metering circuit, it's ok any meter you want to use, just add the buffer and inverter and then replicate the gain cell on the other side so you can measure that from a DC voltage.
JS
About the metering circuit, it's ok any meter you want to use, just add the buffer and inverter and then replicate the gain cell on the other side so you can measure that from a DC voltage.
JS