Tires are a good option if you want to or can go bigger. Maybe you can swap them from your mower if those have a larger radius.
What I would do is raise the table to drop height and remove the hitch from the tractor with a floor jack. Then, lower the hitch until the end forks are just on the ground. Is the change an inch, 2 or 5 inches? If its more than an inch or 2, something else is wrong.
BTW: On my 1012, those pushoff feet are pulled back in by springs. If the channels they ride in are rusted up, one or both may not retract fully. If that happens and you lower the table, they will get bent. And thats a Major pain in the buttt. I now just throw my used oil all over the channels. I use a leaf blower to dust off the machinery after each cutting. This one needs special attention around the cross conveyer because the hay will block the levers and links that trip all the operating steps, especially when it gets wet from being rained on.