The 18th-century folk did not bustle -- they wore some panniers (side hoops), but that was mainly a European and more courtly attire. Here they wore what they had and I've never heard of specific mourning or funeral attire ( I used to be a reenactor of this era). The 19th-century folk loved mourning attire, but it was very strongly associated with the Victorians. A good source would be Godey's Ladies Book. I have no idea if their images are online, but a good university library should have some in their stacks. A WONDERFUL source of fashion plates. I've also often seen some plates (the fashion pictures) in antique stores in the photo/drawings areas. There is also an online emporium which focuses largely on the Victorian area called Amazon Drygoods. They have patterns and items for sale including, hats, shoes, gloves, etc. Hoops and corsets, too. By and large though, the mourning clothes were just the same as the ordinary clothes in style at the time, just black. And don't forget mourning jewelry made of the deceased's hair....

check out the costumer's manifesto web site. they have links to serious costuming and to aluminum hats to keep the aliens out, and the ever popular hats of meat. The Victorians in England were the trend setters about mourning attire. It went, black for the first year, black and deep colors like deep blue or purple, accessorized with black shawls, bonnets and armbands, third year was regular clothes with black armbands, and after that you were on your own, with your hair jewelrey, of course. anything about mourning attire in Victorian England will give you the shapes you want.