I realise it's not for everyone but tens of thousands of dollars also buys a lot of batteries, inverters and alternators.
I swapped dead 10 and 30kva units for lots of lithium, 10kw inverters and 5000w of solar, came out ahead in $$$$ and no more noise, maintenance etc.
Again, not for everyone but perhaps worth a back of a napkin sanity check??
Good luck.