Ok - so I missed it the first time around.
The subframe is not listed with the BT601 backhoe.
It's listed with the tractor itself. So if you go to the Kubota site and go to the "PARTS" link - then drill down the Illustrated Parts List - put in BX24 for what you're looking for - you will find the parts illustration showing that the subframe for the backhoe is separate pieces.
It's shown under the " Front Axle" - and then "Sub Frame" section.
Some of the other sub-assemblies for the backhoe mounting frame are shown under other sections - but they're all in there - and they're all separate pieces.
The complete frame is shown under Front Axle - and then Front Frame.
Looks like the complete frame is part number K2581-92110
If you dig thru the BX2360 parts list - and find that the frame is the same number - well then I'm pretty sure that your BX24 backhoe and it's subframe will likely bolt right on.
One thing to bear in mind when doing stuff like this is - manufacturers don't want to go out and create a whole bunch of distinctly different parts to support a range of products. They will use as many common parts as they can get away with.
So when you're talking about something like a BX2360 and a BX24 - it's much more likely than not that there will be a huge number of common parts between the two.
And your crushed BX24 isn't worthless. Even if you part it out for parts it will still pull some money back in.
Somewhere out there there might be a guy who dropped a tree on the front of his tractor.
Online parts catalog:
Kubota Tractor Corporation - Parts List