i struggled with this when I broke my leg skiing in 2009. I learned that our Mark I boat is actually etremely well suited for handipaped access once on board.
However, Mark II boats have a bunch of different things missing that Mark I boats DO have.
The handhold on the sliding hatch does not exist on Mark II boats. I find that between that handhold and the two on the sides going down below, I was just fine with limited mobility and leg strength.
The Mark I boats have a handhold above the galley sink along the centerline of the boat, and another one just forward of the mast. IIRC, Mark II boats do not. On my boat I can go from the cockpit to the V berth literally without my feet hitting the sole, which I've actually done when heeled beating upwind in heavy conditions: hatch and companionway handholds down the stairs, galley sink handhold, turnbuckle on keel stepped mast, forward handhold and V berth. Monkey-time sometimes.
I suggest, if you can,that you find a Mark I boat and see the differences and see what you can work up for your boat.
Good luck, I know, physical limitations can be quite challenging. Once I figured how to get on the boat from the dock with crutches, I was just fine.