I had the same amd since 2017 I am happy with this replacement for 130 euro incl. 21% tax:
It is a modern design using a Microchip PIC processor and a dual 16 bit sigma delta ADC.
Yes, you can re-use the existing cabling, fuse holders and the 500A/50mV shunt of the Xantrex.
Or you use the TBS supplied one, pull a new CAT5 and do not forget to fit their fuses.
Note that you cannot measure the 12V starter battery as "aux" battery without using an extra isolation amplifier as the engine/genset circuit is completely isolated from the service batteries.
Hope this helps you,
SM2k #348 @ Monastir, Tunesia