I don't have a picture at the moment, but what we did is create a step off the entire rear of the carriage.
Barb had two hangers made that attaches to either side of the carriage body frame (we plan on adding another to the center to stabilize it more).
Then we removed the last two slats on the floor, added the hangers and put the slats on the hangers. In effect the last two slats have been lowered about 6 inches across the entire back of the carriage rather than just haveing a little step.
We also added a full step across the back of the cart. I'm not as good as describing it as the previous poster but it does give you a lot more access to the cart as well as providing a rumble seat for the young Amish lads that tagged along when I was first learning to drive our mare with their father. That being said the cart is extra big to fit a 17 hand percheron mare so the back step might not work as a rumble seat on a pony sized cart.
Ok... here are the pictures of the step across the back of the Meadowbrook. We still haven't 'gotten around' to either cutting off the center floor strap remaining when we lowered the last two boards OR adding the third brace we intend to add to stiffen the center of the step. But it works for us very well without lengthening the step. I've seen vehicles that come this way with step hanging off back of the normal Meadowbrook, but we didn't want the added length. We couldn't find the piece already made, but Witmers made it for us. If you want to do this let me know and I'll send along measurements.
I do like the double arms at the top for bolting to the carriage basket. Should prevent any forward bending if you step on, which could happen with only a single point to bolt on with. Curve is pretty as well as out of your way.
These are pretty typically done with draft-sized meadowbrooks, they do make it easier to mount. I do suggest you put slats in front of the step so there's no chance of your foot slipping through...nothing like a bit of paranoia.