A wedding dress being modelled on an American doll

The description below is about this https://www.moma.org/audio/playlist/5/293by Rober Gober.

1. Does "The wedding dress was sewn by Gober and modelled on an American doll" mean:

a) Gober has used the clothing of an American doll as a pattern for the sewing of the wedding dress

or

b) Gober has sewn the wedding dress himself and has worn it on an American mannequin"?

2. Does "The kitty litter should remain outside" mean "The kitty litter is usually kept outside the house and is not brought inside"?

Text:

For Douglas, the abject has to do with impurity, an intermixture of elements that should be kept apart. Gober’s installations constantly force things together, such as the juxtapositioning of Wedding Gown with Cat Litter, two plaster-cast bags, against the backdrop of his Hang-Man Wallpaper (all 1989), a staging that brings together ideals of purity and images of guilt, the kitty litter symbolising the absorption of the stench that mirrors the repression of the marginal, whether psychic or societal, of that which is deemed dirty and at odds with the purity of the clean and proper body. The wedding dress was sewn by Gober and modelled on an American doll, to symbolise the ideal social ritual from which homosexuals are mostly excluded. The kitty litter should remain outside, but here in the gallery installation is a reminder of dirt and its eradication. The wallpaper’s repeated image of a lynching in conjunction with a white man lying in bed, taken from an eiderdown box, is intended to probe the question of what troubles the sleep of middle America, reminding us of the bodies that have been and are still being cast out as being different, other, abject.