Bruce Griffiths provided this circuit: FURY_EFC_Translator

I made a simple change by adding an OPAMP (U2B) to invert the output so a positive swing in EFC would result in a corresponding swing of the EFC translation voltage.
Without it, the EFC swing would be inverted.

Again, for simulation purposes, I used a LT1208 OPAMP but in real life I would use a device with better specs.
Also, in real life, VREF (+5V) would be provided my an AD586 (preferably an AD586MNZ).

The Fury ground offset has almost no effect on the OCXO_EFC, as would be expected.

I did not include any output waveforms since they are just DC values.

The note box explains the values needed for different EFC Translation Voltages.

Here is the schematic: