Not directly Aladdin related but Animation Backgrounds blogged a set of digitally recreated backgrounds from the 1995 Disney feature film Pocahontas. As you’ll probably know a decent part of the Aladdin crew where also onboard Pocahontas at the time.
Blogger Rob Richards from Animation Backgrounds posted 7 backgrounds from Aladdin. He used a painstaking technique by layering multiple frames over each other then erasing parts that don’t fit. Usually that means characters that obscure the background. He explained how he does that in this post using Mary Poppins as an example.