Do solid tires last?

[secuono]

I'm so sick of regular tires, they're always flat when I turn around.
I use it for moving halloween decor.
So, I'd like to get tires I'll never have to worry about again, at least not every bloody week!
Anyone know how long solid rubber ones last?
How do you measure to fit new sizing? I want to up the diameter, as you can see, there is some space before the metal blocks it. And it's not a typical type, just holes in metal holding the center, so I could potentially widen if necessary. Idk all the right terminology.

 

[Standards Equine]

Have you tried to slime your tires? I'd bought a bottle last fall and did all of mine and didn't have a single flat this year. Just two got low when the weather cooled down. Looks like you have a problem with seating on your rims. Perhaps your inner tubes need to be replaced?