IH Dexter,

Good luck with your new tractor

The water issue is due to infiltration via the rear windshield seal.
It is dried and shrinking and allowing water to enter...I had the glass shop remove and replace mine with a new seal that I had purchased from Performance Parts. Totally fixed the problem. ($75 labor plus the seal)

You could also use a silicone sealant but it is difficult to end up with a good working fix that looks acceptable/decent. Plus, silicone is only temporary for a couple of years and will be hard to clean up when you must do the seal replacement afterall.

Oh! Plug up those drainage holes in the trunk to stop exhaust fumes from suffocating you and your passengers or at least ruining the interior

Welcome and Good, Good luck!!