A good corset is a treat to find. Ladies didn't need but a few. Washable garments were worn under and over the expensive corset to save it from wear, tear and washing. And since they were adjustable to size by lacing, a lady could use the same corset for years. She would need to purchase a new one for a major weight loss or gain, or when the fashionable silhouette made a major change. So there weren't as many running around to start with. Then the need of modern gals to buy thse old corsets and try to wear them under stress means there are fewer and fewer still avaible in any condition. Fortunately, there are many wonderful reproductions available now for the enthusiast, leaving the orignals a chance to stay intact.
Here are two grand undergarments we just added at Past Perfect Vintage:
Then, for something a bit more modern: a late 1940s - early 50s Merry Widow style corset in black lace and stretch with front hook and eye and zipper closure. This was made in Western Germany by Triumph of Europe - gotta love that name - and has an oral provenance that it belonged to Rosemary Clooney. Given the shop where the consignor purchased it, it's more than possible.