Very similar to mine:

I made two of these out of three 8' 2x10's
Cut two of them at 54" for the bottom, the second level is the 42" leftovers from the 54" cut. The remaining 8' length has two 30" cuts and the remaining 36" is cut in half. Then I put a couple of 2x4" scraps at then end as stops.
I've not lowered my SVT yet, so I don't know how these would work.
I think they are more sturdy than most steel ramps.
Cost ~ $25 and one hours labor.
FWIW,
TB