Today a selection of Pathe Newsreels I found on their youtube channel dealing with corsets and underwear.
This one from the 50's entitled "Grandma's Corsets" is a very interesting look at how underwear progressed from corsets to strapless bras and then to the "corslet" (or corset lite).
Corsets through the Ages, doesn't have any sound, but it's still a very interesting glimpse into how much underwear changed over the first half of the 20th Century. The audience reactions in this one are particularly fun, lots of disgruntled wives less than amused at their husbands ogling women in their knickers!
'secret Lady' Girdle (1960), is also unfortunately silent although very interesting, it features a Victorian themed burlesque act (who actually kind of reminds me a lot of Immodesty Blaise the way she moves), and a couple of the corsets featured look a lot like they could be from the Symmington Collection, although this video did get a scream of terror from me due to the bad lacing technique... Please people, don't lace yourselves or your friends up like that, it's a very good way to injure someone.