All of the items you listed are covered by warranty replacement parts. Here are the numbers thanks to Charliebrn's postings:
(Grip Kit (Kubota part number:K2581-9557-0) Contains all the plastic handles and lever sleeves for the levers and knobs. Seems that they go on much tighter than the old ones.
Cluster kit: This is the dash cluster for all the gauges. The first design could accumulate moisture inside, or the hour meter may not work properly
BX1850 Part number K2501-6250-2
BX2350/24 Part number K2581-6250-2
For the original fenders that had a tendency to break...
Fender Kit: Part number K2581-95522
Step stay kit: These are the new brackets that support the floorboard. This is extremely heavy-duty. This has to eliminate any floorboard flex at all. Very impressive fix.
BX2350/1850 part number K2581-9554-0
BX24 Part number K2592-9554-0
I love my BX-24 and have been very happy with Kubota's stepping up to take care of the issues with this tractor. If you have issues they are with your dealer. I agree with skyco that you need to go to Kubota directly.