The trailer is 77" wide inside-to-inside.
There is a built in trimmer rack on the outside, but I use that to hang a ladder on. I built a metal trimmer rack that hangs on the inside of the trailer and it holds 4 trimmers.
I can get some more pictures of the trailer and the inside when I get it out of the garage tomorrow.
The Toro is a 21" personal pace Super Recycler.
Not exactly sure what you mean by "brake axle"? The trailer has a braking system which does activate a brake drum on the rear axle.
If someone needs me to meet them half way or something, I could probably work it out.