I'd say it was sold new as a Bolens G152 which is the imported-by-Bolens Iseki TX1300. Unless someone attempted to "convert" it to avoid the gray market tractor thing but that, at least to me, wouldn't be worth doing. Even the Bolen's branded tractors had nameplates that stated Iseki on them so that won't help much. I haven't really seen any "Blue Isekis" have the auxiliary hydraulic mount on the fender, but that doesn't mean it wasn't added or that the Isekis didn't come with them. If you scrape off some of the paint and find blue underneath then you'll know one way or the other. I don't think Bolens repainted them but instead ordered them directly in white from Japan, at least that would make a lot more sense. Also the sticker like the one under the front left hood grill leads me to think it's an official Bolens. The front tire size seems to be indicative of Bolens too. I think all the Isekis had the skinny tall front tires for that particular model. The linkage for the fuel lever was opposite on the official Bolens version - off was to the rear. On the Isekis, off was pushed all the way forward.
They are a relatively easy restore in my opinion. They clean up real nice since there is little in the way of sheet metal (compared to a car at least) and you can't really hurt the rest of it in terms of damage and rusting away. Too bad it wasn't 4wd, they are a little more fun but the 2wds are still great tractors. Good luck with the project and keep us in the loop. I'd post in the Iseki forum as that is a closer match and you'll find a lot more applicable information there.