I have a used KwiKee step assembly I took off my 2003 National SeaBreeze for sale. $100 plus shipping.
Here is the add in Classified section;
Kwikee motorized Step - $125
I have a Kwikee; model 28 series, motorized step for Motorhome.
It is 23-1/2"x 10-1/4" step with about a 7-1/2 rise.
The serial number is; 133914
It includes the step controller; The part number is; 90950600, serial number; 0157936.
It was taken off of our 2004 Motorhome (11,000 miles) and replaced with a dual step; it was functioning fine, it just wasn't high enough for us, when we park on uneven terrain..