ain't too much out there in the aftermarket for kubota stuff in general. Pretty much nothing to my knowledge for cab glass. OEM or used is your only option, that or maybe you can get someone to cu$tom make you one
used market? Glass is one of the most commonly damaged tractor parts which makes finding one used considerably harder and likely more expensive
went through this recently with a guy's kawasaki brute force 750. Engine trashed, and that is the #1 cause of "sending it to a junkyard"-thus there were zero options out there for used engines. Had to rebuild it piece by piece, at almost 10 grand.