Electric Entry Step motor...Problem discovered!...with pics

They are Ford power window motors. I want to say some year and the proper side of some Taurus.
A four-door Ford will have at least TWO motor part numbers because they are Left and Right. Might have Four: Front Left, Rear Left, Front Right, Rear right.
There are "motor saver kits" for older Ford motors, the ones with a round motor not your squared off one.
Before you buy a motor, check the "Help" rack at the chain auto stores, or ask a counter person at NAPA.
Also, you can make a filler, say a strip of aluminum, to wrap around the hub to take the space out of it. No safety issue there, since the electric step stops when current draw tells the controller the step has hit something. That "something" is usually full extension or full retraction, but if you're next to a curb and it extends, it'll stop on current limitation. The Fords aren't that way. They need a slip clutch (the part that failed on your step) to prevent overloading the motor if somebody holds the switch against top or bottom. Or somebody gets caught in the window. RV does not. Uses the same Ford motor, just with a different limit arrangement. On the round motors, we'd drop balls from old wheel bearings into the pockets that were left when the clutch fell apart.

This Amazon Page will give you an idea. Notice there are two products mentioned. One is the Gear WITH Clutch Rollers and the other is Rollers Only. You might find you could improvise something using the rollers as material to repair the setup you have. Given of course your motor isn't one of the "Select Models."