Re: So just swap the whole processor board.
"Just askin' (apologies if it's a daft question)."
Not a daft question. I'm not familiar with the product.
If the drives are nothing but data and the whole thing is driven by firmware on the processor board then it would be a tad difficult. It would depend on being able to find an alternate device with sufficiently similar firmware which would be entirely down to the software being generic. Without going off & researching that I've no idea whether it is or whether it's proprietary.
If the drives have an OS on them then it would depend on the OS including the right drivers. There's always a problem, even with general purpose OS's, of having support for newer or even older hardware.
Short answer, "similar-enough" might not exist.