I had to make a special ramp for one side of my TT, to park in my driveway. Unfortunately, my TT is in winter storage and the ramp is stored in the TT.
Here is an image of my blocking at my old place. You will see in the middle board is not continuous, it helped to lighten the unit, and gave a good hand hold. I cut the ends of each board about 45 degrees, and gave a step point so the weight is on the board before trying to push up the next board. I screwed the boards together with deck screws.
In your case I might add a stop block just so you know where/when your up on top.