For scooter rental, Deckerts. I will see if I can find their number for you when I get home. They come up as a dental supply place on an internet search. Scooter rental is a secondary business but they rent well maintained ECVs.
Be sure to grab a handicapped visitors guide in DL. You go in the exit on a lot of attractions.
We've had success with Deckerts as well.
And @The Hunchback gives good advice on the map! FYI the attractions that issue wheelchair return times will be found in Disneyland, DCA being a new park has wheelchair accessible lines.