Kubota M59, Kubota L3800, Grasshopper 428D, Topkick dump truck, 3500 dump truck, 10 ton trailer, more lighter trailers.
Why would you put those tires on and run stock turfs on the front? It also appears to have 800 pounds of weight on the front. It very likely has higher ground PSI on the front than stock turfs on the rear would. I guess it's possible they had something heavy on the 3 point hitch which significantly reduced the load over the front axel.
I would say he probably had $9,500 laying around and couldn't come up with anything worthwhile to blow it on. Or, that might just be a closet dragster disguised as a tractor.
I wonder if it might be set up for steep hillside mowing, with a heavy rear mower needing that added weight out front. If the hill gets too steep, those slick rears may let it slide sideways instead of tip.
2009 Kubota RTV 900, 2009 Kubota B26 TLB & 2010 model LS P7010
Tires like that are worthless for any purpose on a tractor. Absolute zero traction on grass, maybe good on asphalt though. Even regular turf tires can get stuck where a dog pees if you have even a slight incline. I wouldn't give 95 cents for those much less $9500.
Polo fields would be an area where I have seen "similar" set ups. Some of the really high ends ones are quite picky about tread patterns, but then again I don't recall seeing a high end polo field being mowed by that old of a machine either but wouldn't surprise me that is a whole different crowd of tractor users.