The battery on the U17 Kubota is getting weaker and the load tester carbon showed a pretty bad voltage dro; in the interest of reliability decided to get a new one. Off to the battery store(s) to learn it is a unique size, so....a call to the dealer. Their (Yuasa?) supplier is avoiding their calls and has yet to send the batteries they have ordered. They are able to get one from another dealer. Because the space for the battery is so small and exact there was little room for a 'will fit'. Although a gel battery did appear to be not a bad fit, but there was only one at the battery store and someone else had called and bought it but had yet to pick it up. We have bumped into these shortages with seemingly increasing occurance on surprising types of things.
Are you familar with BCI groups and sizes? Look for a chart, they are all over the internet and give dimensions. Many size numbers are close to the others and there is no rhyme or reason. Pick one that might fit and call the battery store and ask about a "Group xx" and if they can't get one go back to the chart for a "group yy" and so on.