I would have them fill the hole, throw away the tube and have it filled with foam. I foamed the front tires on both of my tractors and it's been great. I used to get flats monthly, and sometimes even more often. Once the tire breaks down from a certain number of flats, the rubber in the tire is never going to be any good. But with foam, the tire will completely fall apart and you still wont have a flat tire. I've had foam in my R1 tires that are just like yours, for ten years now. They where brand new when I had them foamed because the previous tires where just not worth trying to get another ten years out of them. My tires have holes in them, the tread is breaking off, and it just keeps on going. I'll probably have to replace them in another five years, but until then, I know that I wont' have any flat tires!!